How does Facebook define Ad Frequency?

Frequency is the average number of times each person saw your ad. This metric is estimated and calculated using sampled data. The frequency formula is ‘ad impressions divided by reach’. Frequency can help build awareness and ad recall by showing your ad multiple times to people in your target audience. The average frequency number can be 1 to 3 per ad set or it can be a much higher number depending on multiple factors, such as your campaign’s budget and the audience size you are targeting.

Before diving into details, let’s remember that optimal frequency numbers are highly depending on the objective of your campaign and cross-channel marketing efforts. Branding versus performance goals need different ad frequencies.

What makes an impression and frequency number?

Not all ad impressions are equally defined and not all impressions are qualitative.

Some factors to consider when talking about ‘ad impressions’:

  • Scroll speed of the content consumer
  • Format of ad that is shown
  • Platform and placement where the ad is shown

Some factors to consider when talking about ‘frequency’:

  • Size of the audience that has seen the ad
  • Content of the ad that is shown
  • Attention span of the user that is consuming the ad

High or low frequency numbers depend on multiple variables and combinations. Is your frequency number ‘high’ or ‘low’? It really depends. 

Let’s review some example scenarios to think about this number more smartly.

Note: The following examples are simplified to ‘one user’ scenarios for explanational purpose.

Scenario 1

A user is browsing the Instagram Feed and is scrolling fast. The ad that is shown is not ‘thumb-stopping’ and the ad has appeared on screen for only 0.20 seconds. Instagram counts an ad impression from the moment the ad appears on screen (greater than 0 pixel and greater than 0 seconds). This would be 1 impression for that user.

The next day, the same user is browsing Facebook Stories and watches 3 seconds of the same ad. The ad frequency would now be 2 impressions for that same user. It’s the same ad, but different placement. 

The advertiser is now looking at a report that shows a frequency of 2. 

Actually, the user did not pay attention to the first ad impression, so the more accurate frequency number would be 1 instead of 2.

Scenario 2 

A user is browsing the Facebook Feed at a slow pace. A video ad appears, but the user has changed the settings to not auto-play videos when using a mobile device. The video ad and thumbnail has appeared on screen for 2 seconds and the user has read the ad’s description, but did not watch the video. Facebook counts an ad impression from the moment the ad appears on screen (greater than 0 pixel and greater than 0 seconds). This would be 1 impression for that user.

The next day, the same user is browsing Facebook Feed again and sees the same video ad. The users chooses to hit play and watches the video for 15 seconds. The frequency would now be 2 ad impressions for that same user. It’s the same ad, the same platform and placement, but different attention spans.

The advertiser is now looking at a report that shows a frequency of 2. 

The user did pay attention to both ad impressions. And even when the first interaction would rank lower than the second one, the frequency of 2 would be more accurate than in scenario 1.

Scenario 3

A user is browsing the Facebook Feed and is scrolling at a slow pace. The user visited an online shop and is now seeing a dynamic catalog ad showing different products in a carousel ad. The user interacts and swipes through the products. The user has seen many products, but it is still counted as 1 ad impression in reporting. 

Later that day, the same user is browsing Facebook Feed again and sees the same carousel ad, but the ad is now showing other products. the ad count frequency is now set to 2 ad impressions. 

During the same week that same user sees the same carousel ad 5 more time, each time showing a combination of different products. The frequency count for that week is now set to 7.

7 per week is ‘high’ right? Well, not necessarily. It really depends… In this last scenario, the same ad showed different products as it was generated dynamically. Each unique ad creative was therefore only shown once. The more accurate frequency number would be 1 to 2 instead of 7.

Now that the methodology has been cleared up, there are other factors to take into account when reporting on frequency numbers. 

Frequency is estimated

The Frequency number is always ‘estimated’ and it is an ‘average’ number. If you are looking at an average frequency of 3, some users would have seen your ad only once, while others might have seen it 10 times or more, depending on the overall size of people reached.

For action-based campaigns, the manual ‘Frequency cap’ control is not available. This is mainly because the algorithm needs liquidity and ‘freedom’ to adapt frequency per user, based on signals on how likely that user is to take your desired action at the same time your ad is entering the auction. 

Preventing Ad Fatigue

Of course users don’t like to see the same ad too many times. You should prevent this. But how can you prevent this when the number is so hard to interpret correctly? Luckily, there are some best practices:

  • When targeting small segments of audiences, use dynamic ads and/or control frequency capping for ‘Reach’ based campaigns, especially when using ‘static’ ads. 
  • Keep an eye on ‘Ad Relevance’ metrics at the ‘Ads’ level in Facebook Ads Manager, such as ‘Quality Ranking’ and ‘Conversion Rate Ranking’.
  • Keep an eye on overall performance and ‘Cost per Result’. Ad fatigue results in a drop in performance and an increase in ‘Cost per Result’. If that happens, change your static creatives and/or make changes to your audience targeting. 
  • Use automated rules to monitor frequencies, especially for remarketing campaigns that use static ads. You can create a rule to get a notification or even pause your ad from the moment it hits a specific frequency number during a specific amount of time.

Conclusion

So what is the optimal ad frequency? There isn’t an average or fixed frequency ‘number’ that would be optimal, as there are too many variables.

My answer to this question in one sentence would be:

“The optimal frequency is the count needed to generate desired outcomes and to maximize cost-efficient results, using ads that keep triggering your target audience.”

About the Author

Bram

Bram Van der Hallen is an all-round Belgian Digital Marketer and Facebook Certified Professional with 13+ years experience in media planning and buying. Bram talks about Facebook Ads on LinkedIn. Click here to connect with Bram.

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