Key Takeaways

• Frequency capping restricts how many times a specific user sees the same ad within a set time period

• It prevents ad fatigue, improves user experience, and optimizes advertising budgets

• Caps can be set based on impressions, views, time periods, or specific dayparts

• Without proper frequency caps, advertisers risk wasting money and annoying potential customers

• The optimal frequency cap varies by campaign type, audience, and advertising goals

Ever been stalked by the same ad constantly while browsing? That's what happens when there's no frequency cap. As a publisher or advertiser, understanding this simple yet powerful concept can save your campaigns from becoming that annoying ad everyone remembers for all the wrong reasons.

What is a Frequency Cap, Anyway?

Frequency capping is exactly what it sounds like - putting a limit on how often (the frequency) a specific user sees your ad within a certain timeperiod. Think of it as the digital equivalent of "Hey, I've already told you about this three times today, I'll remind you tomorrow instead."

In technical terms, it's a setting in ad platforms that restricts the number of ad impressions delivered to the same user or device. For example, you migt set a frequency cap of 3 impressions per user per day, meaning after someone has seen your ad three times, they won't see it again until tomorrow.

Why Should Anyone Care About Frequency Caps?

There are three main reasons frequency capping matters:

1. Prevents Ad Fatigue

Seeing the same ad over and over doesn't make people more likely to click - it makes them annoyed. Research from Meta shows diminishing returns after a certain number of exposures, with user engagement dropping significantly.

2. Optimizes Ad Budgets

Without a frequency cap, you could waste a huge chunk of your budget showing the same ad repeatedly to a small segment of users, rather than reaching a wider audience. As Strategus explains, capping frequency helps distribute your impressions more efficiently across your target audience.

3. Improves Overall User Experience

Nobody likes being bombarded with the same message. By limiting exposure, you're respecting user experience, which can actually improve brand perception in the long run. According to Adglare's best practices guide, better user experience translates to higher engagement rates.

How Does Frequency Capping Actually Work?

Frequency capping relies on identifying unique users through:

• Cookies (for web browsers)

• Device IDs (for mobile apps)

• IP addresses (less accurate but sometimes used)

• Logged-in user accounts

When an ad request is made, the ad server checks if the user has already reached their cap for that ad or campaign. If they have, the system serves a different ad instead.

There are several types of frequency caps:

Setting the Right Frequency Cap

Finding the perfect frequency cap is more art than science, but here are some starting points:

For Awareness Campaigns

Higher caps work better here - maybe 5-7 impressions per user per week. The goal is to build familiarity with new products or services, so more exposures (within reason) can help.

For Direct Response/Conversion

Lower caps tend to work better - around 2-3 per day. After a few exposures, if users haven't taken action, they're probably not interested.

For Retargeting

This needs careful balance - Improvado's guide suggests 2-3 impressions per day for 3-7 days, then reducing frequency to avoid annoying users who have already decided not to purchase.

Privacy Considerations and the Future

With GDPR, CCPA and the eventual death of third-party cookies, frequency capping faces challenges. As this SSRN research paper points out, most current frequency capping methods rely on tracking technologies that are being restricted.

The industry is developing alternative approaches like:

• Privacy-preserving methods using first-party data

• Cohort-based frequency capping (showing ads to similar groups rather than individuals)

• Probabilistic models that estimate frequency without precise user tracking

Getting Started with Frequency Capping

Most ad platforms include frequency capping features:

• Google Ad Manager: Set caps at the line item or creative level

• Facebook Ads Manager: Control frequency in ad set settings

• DSPs (Like The Trade Desk, DV360): Offer advanced frequency options across multiple sites

If you're just starting, a reasonable approach is:

1. Begin with conservative caps (2-3 per day)

2. Monitor performance metrics closely

3. Test different caps on similar audience segments

4. Adjust based on data, not assumptions

Remember, even though frequency caps technically limit your potential impressions, they actually improve campaign performance by targeting users at the right frequency - not too little, not too much. It's one of those rare win-wins in digital advertising: better for users and better for advertisers.

This article is part of our Monetization Minis series, designed to help publishers and ad tech professionals understand key concepts in digital advertising and monetization.