I write about growth and startups. If you want to continue reading, subscribe to the newsletter. In this post, I open the most common failure that people do when it comes to running Facebook ads and how to avoid it.

Purchased reported in the Facebook Ads editor are not purchases from your Facebook Ads

I talked about conversion tracking in my previous post in more detail. That conversion tracking is the way most people judge the performance of their advertising. It’s taking data from your website and matching it on Facebook in order to tell you how many orders did you get from the ads.

Or that’s what Facebook wants you to believe.

The purchases column in your Facebook ads manager doesn’t actually measure conversions that happened because of the Facebook advertising.

It measures the conversions that Facebook can somehow match with some advertising activity (view or click of an advertisement).

A lot of people might have purchased the product even without the ads on Facebook, but Facebook just takes the credit for that conversion. This means that the conversions from Facebook are not necessarily incremental.

A quick look to check incrementality

If most of your conversions are coming from people who have never visited your website, you have a better chance that your advertising is incremental. You can trust that the conversions that you see on Facebook Ads manager are more likely conversions that happen because of your Facebook marketing.

On the other hand, if a lot of your conversions are from people who have already visited your website, you have a much harder time making sure that the conversions are incremental.

But either way looking just the ratio of conversions coming from retargeting vs. prospecting is just an opening for further analysis.

The first failure - No segmentation

Not having any segmentation of your audience at all. You have broad targeting with no segmentation for people who have already visited your website.

You see your conversions under the campaign and think that at least some of them must be incremental, but don’t have really a good grasp.

If you split the campaign into retargeting a campaign and prospecting a campaign, you might be shocked to see how many of the reported conversions are coming from the retargeting side. Hopefully seeing this makes you question the incrementality of your campaign.

The second failure - Only retargeting and thinking it’s incremental

You have a little budget or you just want to use the money where it’s most efficient and thus you have only retargeting campaign. It looks like it’s getting a lot of conversions and with a very good-looking cost per acquisition. You are happy with the advertising that you do.

You might have tried to scale up your retargeting campaign, after which you’ve realized that you don’t get any more conversions even if you put more money into it. That might have made you think about the incrementality of the retargeting campaign, but after the test you’ve just scaled the budget down to the levels where the customer acquisition costs are lookign good. You think that you’ve just pushed too hard. Or maybe you acknowledge that not all the conversions are incremental, but some of them have to be, right?

This is where you might be wrong. Or right, it depends on your situation, but luckily there’s a way to test it out.

How avoid the failures and find out if your advertising is going to waste or not?

For this, there is actually a very simple solution in place. What you want to do is to test out how many conversions would you get, even if you shut down a specific campaign of yours.

Instead, you have to do this all by yourself, you can use Facebook’s own tool for a holdout test. It’s an easy way to test for incrementality, where Facebook is dividing your audience into two groups, out of which only the other one sees your advertisements. After the test, you can easily see that what was the incremental impact of your campaign.