The Imperfection of Facebook Ads Frequency Capping

I love to use Reach optimization. It’s only an option for the right situation, but one reason I use it is for Frequency Capping. A small problem, though, that I recently uncovered: Frequency Capping is imperfect. Facebook doesn’t enforce a strict cap.

In this post, we’ll talk more about the following:

  • What Frequency Capping is
  • How it’s supposed to work
  • The imperfection
  • How to detect and control it
  • How much it matters

Frequency Capping

When you use Reach Optimization, advertisers have the ability to put a cap on the number of times a user can be reached. This feature is unique to this specific optimization method.

A Frequency Cap is set from the ad set within the Optimization & Delivery section.

Facebook Frequency Cap

The default is 1 impression every 7 days, but you have full flexibility to set it at whatever you want.

The Imperfection

I’ve used Reach with Frequency Capping for years, but I’ve never had doubts about its execution — at least until recently.

I’m running a test that relies entirely on Frequency Capping running the way it should. My goal is to reach all or most of my Facebook page followers with a single ad. To do that, I used a frequency cap of 1 impression in 90 days.

When I created this ad, the copy was clear about my goals and how it was created. I indicated that each user should only see the ad once.

And then I received a comment from a user indicating they had seen it multiple times. At first, I didn’t worry much about it. But, it happened often enough that it raised some doubts.

If you take a closer look at the settings for Frequency Caps, there’s a message from Facebook that I believe is relatively new (I don’t recall seeing it before).

Facebook Frequency Cap

The message:

As part of our efforts to regularly update our systems and processes, we’ve made changes that may result in some people temporarily seeing your ad more times than the maximum frequency you set.

Facebook isn’t clear why, but they won’t always strictly enforce these caps.

It makes sense that it’s impossible to guarantee perfect enforcement. For example, you could conceivably reach a user in two places at the same time on two different devices. I’m okay with imperfection.

But this was sounding less precise than I’d like.

How to Detect and Control it

Recall that I set this up with a frequency cap of 1 impression per 90 days. Since the campaign hasn’t been running for 90 days, the average frequency should be somewhere around 1.00.

Instead, my overall frequency for this campaign is currently 1.14. While that’s certainly close to 1.00, it represents about 18,000 extra impressions that I didn’t want to pay for.

Reach Impressions Frequency

That’s an unfortunate waste.

One of the first messages I received about this was from a user who said they were seeing the ad in the Instant Articles placement. We can actually do some digging to see if this placement is problematic.

Within Ads Manager, you can run a Breakdown by Placement.

Facebook Breakdown by Placement

Some of the frequencies stuck reliably close to 1.00:

  • Facebook Groups Feed (Mobile App): 1.00
  • Facebook Stories (Mobile App): 1.00
  • Facebook News Feed (Desktop): 1.00
  • Facebook News Feed (Mobile Web): 1.00
  • Instagram Explore (Mobile App): 1.00
  • Facebook Video Feeds (Mobile App): 1.01

Truthfully, all but two placements were below the overall average of 1.14:

  • Facebook In-Stream Video (Mobile App): 1.15
  • Facebook Instant Article (Mobile App): 1.38

Not only was the Instant Article placement significantly higher than anything else, but it also represents 12% of the ad set’s impressions. Considering I turned this placement off some time ago after figuring this out, that’s a lot!

Does it Matter?

Normally, I wouldn’t even notice this because I wouldn’t care about reaching people more than once. So, this is unique.

Ultimately, you will need to decide whether it matters. Does it truly matter whether you reach people with 1 impression every 7 days or whether you reach some people twice? Granted, that’s waste that will be charged to your account, but my feeling is that there are bigger issues to worry about.

The main thing is to be aware of it. It does appear to be a new issue, based on the message from Facebook. Maybe it’s something that is in the process of being corrected. Regardless, you can use Breakdown by Placement to spot whether it’s an issue for specific placements. At that point, you could choose to turn those placements off.

Is there something unique to in-stream video and Instant Articles that make frequency difficult to control? Maybe. Or it’s entirely possible that what I’m seeing is random and not unique to those placements.

Your Turn

Do you use Frequency Capping? Have you seen this issue before, and does it matter to you?

Let me know in the comments below!