GAM Open Bidding for Mobile Apps: Setup and Tuning

GAM Open Bidding for mobile apps: SSP onboarding, bidder approval, yield group configuration, floor and priority tuning, and the failure modes operators actually hit.

GAM Open Bidding (formerly EBDA) is a server-to-server SSP auction available only on GAM 360 with an active AdX account. Setup requires: accepting Open Bidding terms, onboarding each SSP bidder individually (2-business-day approval), updating app-ads.txt with each bidder's seller entries, and adding approved bidders to a mobile-format yield group with OS-level targeting. Approved bidders frequently show zero impressions in the first 7-14 days while the auction calibrates and the bidder's pretargeting system adds your network. Silent fill loss occurs most often from a missing app-ads.txt entry, a COPPA filter, or a bidder that requires a third-party SDK to render creatives.

The Open Bidding access path

Open Bidding requires two account conditions that are neither self-served nor guaranteed: GAM 360 tier access, and an active AdX account linked to that GAM instance.

If you log in to GAM and do not see Delivery > Bidders, you are on the free tier. The feature does not appear in free-tier GAM accounts. Most third-party setup guides skip over this requirement entirely. The access gap is where most operators stall before setup begins.

The three paths to GAM 360 access

The first path is a direct Google contract. Google negotiates 360 access with publishers that meet their volume and quality threshold. The threshold is not published, but accounts running substantial monthly impressions across high-value inventory are the typical profile. This is not self-served and is not fast.

The second path is Scaled Partner Manager (SPM) access. SPM partners are Google-authorized technology companies that provide 360-equivalent access to publishers under a managed relationship. Open Bidding is available through SPM access.

The third path is Multi-Customer Management (MCM). An MCM parent with GAM 360 can extend Open Bidding access to child publishers. For mid-size mobile operators who have not yet hit a direct 360 threshold, MCM through an authorized technology partner is the practical route. The full access path is covered in the Google MCM Manage Inventory Operator Guide.

For operators deciding whether to stay on AdMob or move to GAM in the first place, the AdMob or GAM for Mobile Apps decision framework covers that decision before you need to think about Open Bidding at all.

The AdX requirement

Open Bidding requires an active AdX account linked to the GAM 360 instance. You cannot enable Open Bidding in a GAM 360 account with no AdX link. The bidder list at Delivery > Bidders is only active once AdX is linked. If you have GAM 360 but AdX is pending approval, the Open Bidding setup must wait. The AdMob Approval Checker can help confirm account link status before starting.

Accepting Open Bidding terms

Before the first bidder onboarding, accept the Open Bidding terms via Delivery > Bidders > Go to Open Bidding. This is a one-time account-level step. The addendum covers Google's 5% revenue share for demand facilitated through Open Bidding.

If you've decided Open Bidding is the right demand layer to add and want the full picture of what it sits alongside in your stack, see GAM Demand Options for Mobile Apps before continuing here.

Pre-flight checklist before your first bidder

Each of these conditions must be confirmed before onboarding a bidder. Operators who skip one will complete the bidder form and then see fill that never arrives.

AdX active and linked. Confirm your AdX account is in active status, linked to GAM via Admin > Linked Accounts, and set as the primary exchange for Dynamic Allocation. An AdX account approved but not set as the primary exchange does not participate in the unified auction.

Open Bidding addendum signed. Navigate to Delivery > Bidders. If you see a prompt to accept Open Bidding terms, accept them before proceeding. Adding a bidder without completing this step will not complete the configuration.

Payment and tax information current. Google handles Open Bidding billing on behalf of all SSP bidders and remits to publishers on a Net-30 cycle. Confirm your payment profile and tax form are current in Admin > Billing Settings before adding bidders.

app-ads.txt prepared. Open Bidding requires that each approved bidder's seller information is in your app-ads.txt file before their demand serves. The file lives at the developer domain root (the domain declared in your app store listing, not the app's marketing website). Format: [domain], [publisher-id], DIRECT, [certification-id]. You will need to add the entries for each new bidder at the time of approval. Entries come from the bidder's publisher documentation. A missing entry results in that bidder's buyers seeing an unauthorized selling relationship, which blocks their demand silently. The full app-ads.txt implementation reference is at app-ads.txt Enforcement and Implementation.

Mobile app registered in GAM. The app must be registered under Inventory > Apps and associated with its app store listing. For iOS apps, a live App Store URL is required for live demand. Unpublished apps will register but will not receive full programmatic demand through Open Bidding.

GMA SDK integrated and serving. Open Bidding runs through the Google Mobile Ads SDK. The SDK must be integrated and serving impressions before Open Bidding demand can compete. Most Open Bidding bidders cannot serve to a device that has not initialized the SDK correctly. The full SDK integration reference is in the Google Ad Manager for Mobile Apps: Complete Operator Guide.

The bidder approval process

Not every SSP is available in GAM's bidder list, and not every available bidder will approve your publisher account.

How the bidder list works

The list at Delivery > Bidders > Go to Open Bidding shows SSPs that Google has approved to participate in Open Bidding. This is not an open list. SSPs must apply to Google and establish an Open Bidding account through a Google account manager. As of 2026, approximately 40+ SSP bidders are available, with regional restrictions on some (Ad Generation is Japan-only; MobileFuse covers US and Canada). The list changes as partners are approved, suspended, or deprecated.

The approval process

When you select a bidder and click "Onboard online now," you are starting a bilateral approval. Google processes the request on their side; the SSP reviews your publisher profile on their side. The typical timeline is approximately 2 business days per bidder, but it varies. Some bidders approve publisher requests automatically within 24 hours. Others conduct manual inventory reviews that take 5-7 business days.

During the SSP-side review, the SSP evaluates your app's content category, traffic volume, and quality signals. Apps in sensitive content categories may be rejected by specific SSPs even if the content complies with Google's policies. Apps with very low daily active traffic may be deprioritized. The SSP's decision is independent; Google cannot override it.

Bidder status and escalation

Bidder status in GAM shows as Pending while both sides complete their review. Once both approve, the status changes to Approved. GAM does not send an email notification; check Delivery > Bidders directly.

If a bidder shows Pending for more than 3 business days, the delay is on the SSP side. Contact the bidder's publisher support with your GAM publisher ID. Your 16-digit publisher ID is in Admin > Networks. Do not contact Google for bidder review delays; they do not have visibility into the SSP's approval queue.

The post-approval window

Approval does not mean immediate fill. After a bidder is approved, the bidder's pretargeting system must add your GAM network to their active request targets. This is an SSP-side configuration step. Expect 2-5 business days after approval before the bidder begins submitting bids, even with correct yield group setup. The first 7 days of callout data are not reliable performance signals.

Setting up your first bidder

Step 1: Accept the partnership agreement. From Delivery > Bidders > Go to Open Bidding, locate the bidder and click the name, then "Onboard online now." You will be directed to the bidder's site to complete their publisher agreement. After completing it, return to GAM.

Step 2: Complete the GAM-side acknowledgment. Back in GAM, click "Continue" on the bidder configuration screen, then "Acknowledge and agree" to send the Open Bidding request. The bidder status changes to Pending.

Step 3: Update app-ads.txt. While the bidder approval is pending, add the bidder's seller entries to your app-ads.txt file. Get the required entries from the bidder's publisher documentation. Deploy the updated file to your developer domain root. This step must be complete before the bidder goes live.

Step 4: Create or update a yield group. Once the bidder is approved, navigate to Delivery > Yield Groups. Either add the bidder to an existing yield group for the relevant format, or create a new yield group.

Yield group configuration for a new mobile bidder: name the group to include the bidder name and format (for example, "Magnite_iOS_Interstitial" or "PubMatic_Banner_Android"). Select the specific format the bidder will compete for. Set Inventory type to Mobile app. Add specific ad unit targeting. Set OS targeting to iOS, Android, or both. If a bidder has stronger demand for one OS, configure separate yield groups per OS from the start so you can set different floors later.

Step 5: Add the bidder as a yield partner. In the yield group, click "Add yield partner." Select the approved bidder. Integration type: Open Bidding. The yield group allows a maximum of 10 Open Bidding yield partners per group.

Step 6: Set Default CPM. For new bidders with no performance history, Dynamic CPM is not yet available. Set a Default CPM at or slightly below your AdX average eCPM for the same format and geo. This gives the bidder a realistic entry point to win impressions during calibration without requiring it to beat AdX on every impression from day one. The floor logic is covered in detail in the next section.

Step 7: Save and activate. Save the yield group. Confirm it is active, not paused. Within 24-48 hours of activation, assuming the bidder has completed pretargeting, you should see bid callouts appearing in the yield partner report.

Yield group structure for mobile apps

The yield group structure decision is the most consequential configuration choice after bidder approval. A poorly structured setup limits bidder performance and makes the yield partner report difficult to use.

Why format-specific yield groups are required

Mobile app formats have fundamentally different economics. Rewarded video eCPMs are 5-10x higher than banner eCPMs in most markets. Interstitials sit between them. A yield group that contains both banner and interstitial inventory for the same bidder blends these economics and makes floor-setting at the right granularity impossible. Structure by format: one for banner, one for interstitial, one for rewarded, one for app open if relevant.

Why OS-level yield groups matter

iOS and Android have structurally different eCPMs with most SSP demand. iOS inventory typically commands higher clearing prices than Android in the same geo. Separate yield groups for iOS and Android within the same format let you set appropriate floors per OS and measure per-OS bidder performance without blending the data. The Operating System targeting field in yield group configuration appears only when Mobile app is selected as the inventory type; it does not appear for web inventory.

The recommended production structure

For a mobile operator with banner, interstitial, and rewarded inventory:

  • [BidderName] / Banner / iOS
  • [BidderName] / Banner / Android
  • [BidderName] / Interstitial / iOS
  • [BidderName] / Interstitial / Android
  • [BidderName] / Rewarded / iOS
  • [BidderName] / Rewarded / Android

This produces 6 yield groups per bidder. For operators with multiple bidders, this scales. The overhead is justified by the reporting granularity and floor-setting control. Operators who collapse all formats into one yield group cannot set format-specific floors and cannot isolate which format is underperforming for a given bidder.

Ad unit-level targeting vs network-level

Target the yield group at the ad unit level (specific banner units, specific interstitial units) rather than at the network level. Some bidders have shallow demand for specific content categories or placements. Ad unit-level targeting gives you the ability to exclude specific placements from specific bidders without touching the overall yield group configuration. For the broader demand architecture that gives this structure its context, see GAM Demand Options for Mobile Apps.

For operators thinking through how this compares to a waterfall mediation approach, Mediation Waterfall vs In-App Bidding covers the architectural decision at the format level.

Bidder priority and floor tuning

The floor and priority configuration is where the revenue difference between a functional Open Bidding setup and a well-tuned one lives. Operators who set floors once and leave them are leaving money. Operators who set them too aggressively are losing fill to no-auction outcomes.

How Open Bidding participates in Dynamic Allocation

Open Bidding bidders compete in the GAM auction alongside AdX through Dynamic Allocation. The unified auction evaluates the highest bid from all Open Bidding bidders alongside the AdX clearing price. The winner serves the impression. There are no explicit priority levels between Open Bidding bidders and AdX; they compete on price. The floor you set in the yield group is the minimum CPM a bidder must meet to participate in the auction for that impression.

Default CPM vs Dynamic CPM

Default CPM is a manually set floor. Useful for new bidders with no history. Set too high and the bidder never wins. Set too low and you sell impressions below AdX clearing prices.

Dynamic CPM uses historical eCPM data collected from the bidder's actual performance to set an auto-adjusted floor. Once a bidder has approximately 7 days of impression history in the yield group, you can switch to Dynamic CPM. After that point, Dynamic CPM is the better choice because it adjusts as market conditions change without requiring manual intervention.

Setting the initial Default CPM correctly

Pull your AdX average eCPM for the same format, OS, and geo segment from the Ad Exchange report. Set the initial Default CPM for a new Open Bidding bidder at approximately 80% of that AdX average. This gives the bidder a realistic entry point without requiring it to beat AdX on every impression during the calibration window. After 7 days of data, evaluate whether the bidder's realized eCPM is above or below the Default CPM. If above, raise the floor to 90% of AdX average. If consistently below, the bidder may not have sufficient demand for your inventory profile.

For the full floor calibration methodology across formats and geos, see Floor Pricing Strategy for Mobile Apps 2026.

The calibration window

Open Bidding bidders typically need 7-14 days to calibrate after their first impression. During this period, the bidder's models are learning your inventory's audience profile and bid distribution. Reported eCPMs will be lower than steady-state. Do not evaluate bidder performance or make configuration changes during the calibration window.

After 14 days, run a yield partner report (Dimensions: Yield Partner; Metrics: Callouts, Bids, Auctions Won, Estimated CPM) to evaluate true performance.

When not to adjust floors

During seasonal periods (Q4, major campaigns), eCPMs across all demand sources fluctuate. Do not adjust floors during a major seasonal spike. Evaluate performance against a stable 30-day baseline, not against a week-over-week anomaly.

Floor calibration for multiple Open Bidding bidders across multiple formats and geos is an iterative process. If your bidder eCPMs are stable but your overall yield is not improving, the issue is usually structural: either the yield group configuration or the floor calibration relative to your actual AdX clearing prices. That is a one-session audit. Book a free 30-minute call.

Mobile-specific gotchas

Each of these follows the same structure: what breaks, why it breaks, what to fix. None of them appear in any single editorial source currently on the SERP.

Gotcha 1: SDK adapter requirement for some bidders

Some Open Bidding bidders for mobile apps require a third-party SDK to be present on the device to render their creatives. These are bidders whose formats cannot be rendered through the standard GMA SDK creative renderer. If a bidder requires an SDK and the SDK is not installed in your app, that bidder's approved demand will not serve.

The symptom: an approved bidder with callouts showing in the yield partner report but zero auctions won. Check the bidder's mobile integration documentation to determine whether they require a third-party SDK. If they do, the SDK must be added to the app and the ad unit mapping must be configured in GAM under Delivery > Ad Unit Mapping.

Use the Mediation SDK Checker to verify adapter compatibility before adding a new bidder SDK. The full compatibility reference is in the Mediation SDK and Adapter Compatibility Guide.

Gotcha 2: app-ads.txt entry missing or at the wrong domain

For mobile apps, app-ads.txt lives at the developer domain root (the domain registered in the app store listing). Not the app's marketing website, not the publisher's web domain. If an approved bidder's entries are missing from that file, their buyers see an unauthorized selling relationship and their demand will not serve. The symptom is identical to the SDK gotcha: callouts but no auctions won.

Verify three things: (1) your app store listing declares the correct developer domain, (2) app-ads.txt is accessible at that developer domain root and not a subdirectory, (3) the new bidder's seller entries are present and correctly formatted. GAM provides an ads.txt coverage diagnostic in Admin > ads.txt. For the full implementation reference, see app-ads.txt Enforcement and Implementation.

Gotcha 3: COPPA and TFUA filters excluding all Open Bidding bids

Apps designated as child-directed (COPPA) or serving users under age in EEA and UK (TFUA) have these flags set in the GMA SDK initialization. COPPA and TFUA flags restrict interest-based targeting and remarketing. Most Open Bidding bidders rely on interest-based demand signals to bid on mobile impressions.

A COPPA-flagged app will see very low Open Bidding bid rates even with correctly approved bidders, because the filtered auction removes the personalized demand pool that most SSP bidders target. This is expected behavior, not a configuration error. If your app is COPPA-compliant and Open Bidding fill rates are near-zero, the constraint is demand-side, not configuration-side. Contextual demand sources may be more effective for child-directed inventory.

Gotcha 4: app-ads.txt not yet crawled after update

After updating app-ads.txt with a new bidder's entries, Google's crawler needs time to validate the file. Bidder demand may not serve for 24-48 hours after the file is updated even if everything else is configured correctly. Do not diagnose bidder fill immediately after adding the app-ads.txt entry. Wait 48 hours and then check the yield partner report.

Gotcha 5: Currency and timezone offset in reporting

Open Bidding revenue is reported in your GAM account currency. If your GAM account currency differs from the bidder's reporting currency, there will be a conversion at the rate in effect at the time of impression. This creates day-over-day revenue volatility in GAM reporting that reflects exchange rate movement, not demand changes.

Separately, GAM reporting data is typically available with a 24-hour lag. The yield partner report may show yesterday's data as the most recent. Do not compare same-day GAM yield data to same-day network data from the bidder's own dashboard. Treat day-level revenue fluctuations under 5% as noise.

Gotcha 6: Native ads are not supported in Open Bidding

Open Bidding does not support native ad formats for mobile apps. If you add native ad units to an Open Bidding yield group, those units will not receive bids through Open Bidding. The yield group targeting will silently exclude them. Native demand for mobile must go through mediation adapters in the standard yield group mediation chain.

Adding bidder N+1: the calibration playbook

Adding your first Open Bidding bidder is an experiment. Adding the second, third, and fourth requires a calibration protocol that most operators skip, which results in either miscredited revenue lifts or comparisons that mean nothing.

Why sequential calibration matters

If you add three bidders simultaneously, you cannot attribute revenue changes to any specific bidder. Each bidder needs a calibration window where they run against your live inventory before you can evaluate their individual contribution. The practical recommendation: add one new bidder at a time, wait 14 days for calibration, run the yield partner report to evaluate, then decide whether to add the next bidder.

What to expect in the first 7 days

Bid rate from the new bidder will be low. The bidder's models are learning your inventory. Auctions won by the new bidder will be a small fraction of total impressions. AdX eCPM may dip slightly as the auction adjusts to the new competitor's bid distribution; this self-corrects.

Days 8-14

Bid rate stabilizes. The bidder's models have processed enough impression data to bid consistently. Auctions won begin to reflect the bidder's actual demand depth for your inventory. Estimated eCPM from the bidder becomes a reliable signal.

After day 14: evaluation criteria

Run the yield partner report. Evaluate three things per bidder: estimated eCPM versus AdX eCPM for the same format and geo, fill rate (auctions won divided by callouts), and contribution to total estimated revenue.

If all three metrics are positive (eCPM competitive with AdX, fill rate above 5%, incremental revenue contribution), the bidder is worth keeping. If estimated eCPM is below AdX and fill rate is below 2%, the bidder is adding auction complexity without revenue uplift. Consider removal.

The leave-it-alone principle

Once a bidder clears calibration and is performing consistently, do not make configuration changes without a specific reason. Changing floors during calibration resets the data. Changing ad unit targeting mid-calibration produces uninterpretable results.

Bidder removal criteria

Operators add bidders more freely than they remove them. An inactive or underperforming bidder adds auction complexity, generates callouts the bidder never wins, and clutters the yield partner report. Establish removal criteria before you need them.

When to remove a bidder

First: persistent low fill rate after calibration. If a bidder has been active for more than 30 days and its fill rate (auctions won divided by callouts) is below 1-2%, the bidder does not have meaningful demand for your inventory profile. It will not improve with more time. Remove it.

Second: eCPM consistently below AdX floor. If a bidder's estimated eCPM is consistently below your AdX floor price, it is never winning the auction. Its callouts are generating server-side requests that never result in impressions. The net effect is additional auction load with no revenue. Remove it, or lower the floor to a level where the bidder can compete if that level makes economic sense.

Third: zero auctions won over 30 days despite bids. If the yield partner report shows consistent callouts, some bids, but zero auctions won over a 30-day period, the bidder is bidding below the floor or below AdX on every impression. This pattern does not resolve without either removing the floor below AdX (sacrificing yield floor integrity) or removing the bidder.

Fourth: signal compliance issues. If a bidder's publisher support contacts you about signal quality concerns, or if you receive a policy notification through GAM related to a specific bidder's demand, remove the bidder before addressing the underlying issue.

Fifth: partner deprecation or bidder list removal. Google periodically removes bidders from the Open Bidding bidder list. If a bidder is removed from the list, their demand no longer serves. GAM does not automatically remove them from your yield groups; they simply stop producing callouts. Audit yield groups for bidders that have been on the list for 30+ days with zero callouts. This pattern usually indicates a removed or suspended bidder.

What removal does not fix

Removing a bidder does not automatically improve AdX eCPM or fill rate for the inventory those callouts were targeting. The revenue from a removed bidder's callouts was already zero. Removal cleans up auction complexity; it does not create new revenue.

Reporting and reconciliation

The yield partner report is the primary tool for evaluating Open Bidding performance. Understanding what it measures, what it does not, and how to reconcile it against bidder-reported revenue is a prerequisite for managing Open Bidding correctly.

Building the yield partner report

Navigate to Reporting > Reports > New Report > Historical. Configure dimensions: Yield Group, Yield Partner. Configure metrics: Callouts, Bids, Auctions Won, Estimated Revenue, Estimated CPM. Add filters for date range (minimum 7 days, 14 for calibration evaluation) and Inventory type (Mobile App). Add OS as a dimension breakout if you have OS-level yield groups. Save this as a template and schedule it to run weekly.

This report gives you, per bidder per yield group: how often the bidder is called (callouts), how often it responds with a bid (bids), how often it wins the auction (auctions won), and the revenue estimate and eCPM from those wins.

Diagnosing approved-but-not-producing bidders

The callouts column is the first diagnostic lever. Zero callouts after 7 days means the bidder's pretargeting has not added your network. Contact the bidder's publisher support with your GAM publisher ID. Callouts present but zero bids means the bidder is receiving requests but not responding: either their system has not yet modeled your inventory, or there is a technical issue with their bidding endpoint. Contact the bidder's publisher support. Bids present but zero auctions won means the bidder is bidding below your floor or below AdX every time. Lower the Default CPM floor or accept that the bidder's demand is not competitive for this inventory.

Reconciliation with bidder-reported revenue

GAM reports "estimated revenue" from Open Bidding, not actuals. The actual revenue from each bidder is reported in that bidder's own publisher dashboard. Discrepancies between GAM's estimated revenue and the bidder's reported actuals are normal. GAM estimates using the clearing price at auction time; the bidder reports actuals after their billing cycle. For reconciliation, the bidder's dashboard is the authoritative revenue figure. GAM's estimated revenue is a yield management tool, not a billing reference.

The Active View gap

Impressions served through Open Bidding bidders are not eligible for Active View measurement in GAM. Active View metrics will only reflect Google demand (AdX and AdMob direct), not Open Bidding demand. This is a reporting asymmetry to note when sharing performance data with advertisers or internal stakeholders.

Common failure modes

Each failure mode below follows the same structure: what you see, why it happens, what to fix.

Failure 1: Bidder shows Pending for more than 3 business days

What you see: bidder status in Delivery > Bidders does not change from Pending.

Why it happens: the delay is almost always on the bidder's side. The SSP is conducting a manual publisher review, their approval queue is backed up, or the partnership agreement on the bidder's portal was not completed correctly.

What to fix: contact the bidder's publisher support directly. Provide your GAM publisher ID and the date you submitted the request. Do not contact Google; Google does not control the SSP's approval workflow.

Failure 2: Approved bidder shows zero callouts after 7 days

What you see: bidder status is Approved in GAM, yield group shows the bidder as active, yield partner report shows zero callouts.

Why it happens: the bidder's pretargeting system has not added your GAM network to their active request pool. Some bidders complete this within 24 hours; others take 5-7 business days.

What to fix: contact the bidder's publisher support with your GAM publisher ID. Confirm app-ads.txt entries for that bidder are live and correctly formatted. If pretargeting is confirmed active by the bidder and callouts are still zero after 7 days, check that the yield group targeting includes the correct ad units and that the yield group is active.

Failure 3: Approved bidder shows callouts but zero bids

What you see: the yield partner report shows callouts, but the Bids column is zero.

Why it happens: the bidder is receiving requests but not bidding. Causes include the bidder's demand models have not yet processed enough data from your inventory (early calibration), the bidder's endpoint has a technical issue, or the bidder does not have demand for your specific app category or geo mix.

What to fix: wait 3-5 more business days. If zero bids persist after 14 days from first callout, contact the bidder's publisher support with the yield partner report showing callouts and zero bids.

Failure 4: Approved bidder shows bids but zero auctions won

What you see: callouts and bids are both non-zero, but auctions won is zero.

Why it happens: the bidder is bidding below your Default CPM floor on every impression, or is losing every bid to AdX.

What to fix: pull the Ad Exchange report to see your current AdX average eCPM for the same format and geo. If your Default CPM floor is above the AdX average for that inventory, the floor is the issue: lower it to 80% of AdX average. If the floor is already below AdX average and the bidder is still losing, the bidder does not have competitive demand for this inventory. Consider removal.

Failure 5: Revenue drops when a new bidder is added

What you see: shortly after adding a new bidder and seeing it win some impressions, total estimated revenue from AdX drops and total revenue is flat or slightly down.

Why it happens: Open Bidding bidders participate in the same auction as AdX. A new bidder that wins impressions is winning them from AdX, not generating net-new demand. If the winning bidder's eCPM is lower than AdX was clearing for those impressions (because the bidder's early calibration bids are below steady-state), total revenue may drop temporarily. This is the calibration cost of introducing a new demand source.

What to fix: wait for the calibration window to complete. Revenue should stabilize or lift after 14 days if the bidder has genuine demand for your inventory. If it does not recover, the bidder's steady-state demand is below AdX for your inventory profile. That bidder is not additive; remove it.

Failure 6: Open Bidding disappears from the Delivery menu

What you see: Delivery > Bidders is not visible in GAM.

Why it happens: either the account is on the free tier, not GAM 360, or the AdX link has been removed or deactivated.

What to fix: confirm GAM tier. If the account was recently downgraded or if AdX access was terminated, Open Bidding access is suspended.

If more than one failure mode from this section applies to your Open Bidding setup, a structured diagnostic is faster than working through each in sequence. Bring the yield partner report and the bidder list and the initial call covers the diagnosis. Book a free 30-minute call.

Frequently Asked Questions

Do I need GAM 360 to use Open Bidding for mobile apps?

Yes. Open Bidding in GAM requires the paid 360 tier. The feature does not appear in free-tier GAM (Small Business). If you do not see Delivery > Bidders in your GAM navigation, you are on the free tier. Publishers who want Open Bidding without a direct GAM 360 contract can access it through a Google-authorized Scaled Partner Manager (SPM) or Multi-Customer Management (MCM) partner. These are Google-approved technology partners that provide GAM 360 access to publishers under a managed relationship. You also need an active AdX account linked to the GAM 360 instance. Open Bidding cannot be enabled without AdX.

How long does a new SSP bidder take to get approved in GAM Open Bidding?

The approval process involves two sides: Google's review and the SSP bidder's publisher review. Google's side typically completes within 24 hours. The SSP's review takes approximately 2 business days for most bidders, but some conduct manual inventory reviews that take 5 to 7 business days. After both sides approve, expect an additional 2 to 5 business days before the bidder's pretargeting system begins sending bid requests to your GAM network. Total time from onboarding to first impressions is typically 5 to 10 business days. If a bidder shows Pending for more than 3 business days, contact the bidder's publisher support directly with your GAM publisher ID. Google does not control the SSP's approval queue.

Why is my approved bidder not winning any impressions?

The most common causes are: the bidder's pretargeting system has not yet added your network (contact the bidder's publisher support); app-ads.txt is missing or missing the bidder's seller entries at your developer domain; the Default CPM floor is set above the bidder's bid range; the app is COPPA-flagged, which filters out most interest-based demand; or the bidder requires a third-party SDK for creative rendering and the SDK is not installed. Check the yield partner report with Callouts, Bids, and Auctions Won as metrics to identify which failure state applies. Zero callouts means pretargeting has not completed. Callouts with zero bids means early calibration or a technical issue on the bidder's side. Bids with zero auctions won means a floor or demand-fit problem.

How do I set up bidder priorities and floors in Open Bidding?

Open Bidding bidders compete in the same Dynamic Allocation auction as AdX. Priority is determined by bid price, not a manual priority ranking. The floor you set in the yield group (Default CPM or Dynamic CPM) is the minimum the bidder must meet to compete. For a new bidder with no history, set Default CPM at approximately 80 percent of your AdX average eCPM for the same format and geo. This gives the bidder a realistic entry point without requiring it to beat AdX on every impression during calibration. After 7 days of data, switch to Dynamic CPM if performance is stable. Dynamic CPM uses historical data to auto-adjust the floor as market conditions change. Do not mix Default and Dynamic CPM for the same bidder across yield groups targeting the same inventory.

Can I run Open Bidding alongside AdMob mediation?

Yes. Open Bidding and AdMob mediation run as complementary demand layers in GAM. Open Bidding bidders compete server-side in the unified auction alongside AdX. AdMob mediation adapters run through yield group mediation chains and are called when the server-side auction does not produce a winning bid above the floor. The standard production architecture is: Open Bidding bidders plus AdX in the server-side auction, with AdMob mediation as the downstream fill layer. The two layers operate in sequence: Open Bidding and AdX compete first, mediation fills the impressions that do not clear the server-side auction floor.

What's the difference between Open Bidding and EBDA?

They are the same feature. EBDA stands for Exchange Bidding in Dynamic Allocation, which was the original product name. Google rebranded it as Open Bidding in 2019. All current GAM documentation uses Open Bidding. Some older operator guides and vendor documentation still reference EBDA. If you encounter EBDA in a setup guide, it refers to the same server-to-server SSP auction available through Delivery > Bidders in GAM 360. The mechanics, requirements, and configuration steps are identical; only the name changed.

Open Bidding for mobile apps works when the yield group structure and floor calibration match your actual inventory profile. Most operators who struggle with it are dealing with a missing app-ads.txt entry, a misaligned floor, or a bidder that never had demand for their specific inventory in the first place. If any of those descriptions fit your current situation, the free initial conversation is the right starting point. Book a free 30-minute call.