It’s crazy what a difference checking one box can make on the success of your Facebook ad campaign.
In November of 2016, Facebook rolled out targeting expansion:
You’ll find this button underneath the detailed targeting section at the ad set level of your campaigns:
Long story short, when you check this box, Facebook will show your ad to people outside of who you have already selected… if they believe those people are likely to convert.
But… does it work?
We decided to put this box to the test!
Facebook Targeting Expansion: The Test
We created two campaigns. They were identical OTHER than one had the box checked and the other didn’t.
This was a website conversion campaign optimizing for people to opt-in for our “Perfect Blog Post Template” Lead Magnet.
We created 14 ad sets…
- One to warm traffic (people who are familiar with your brand)
- Five to various lookalike audiences
- Eight to varying clusters of interests
Here’s a screenshot for those of you that are visual learners:
And here’s the ad on Facebook:
We ran the test for ten days, with a $5,000 budget for each ad set…
…and the results were VERY surprising and unanimous across each ad set!
Facebook Targeting Expansion: The Test Results
When we checked Facebook’s targeting EXPANSION box our cost per lead was 25% higher…
…and it also produced less volume. When we checked the expand box, we generated 322 fewer leads than when didn’t check the box.
The cost per unique click was 17 cents higher when we checked the expand box. 
The conversion rate on the page dropped from 66% to 58% when we checked the expand box. This makes me think that the traffic hitting the page was less qualified for the ad sets where the expand box was checked.
Every one of the above metrics from this test goes to show that checking the expand interest box produced WORSE results for our campaign.
So, here are my thoughts….
1. This Isn’t the End All Be All… You Should Test Facebook Targeting Expansion
Remember, this is just one test.
Although we saw a significant difference in our metrics when we checked the expand interest box, this doesn’t mean that this will be the case 100% of the time. 
There are a few factors here at play, like the objective. We were running a website conversion campaign for this test. The expand interest button could behave differently under different objectives (I wouldn’t expect to see anything drastically different from what we saw, though).
Moral of the story… if you’re curious, run this test on your own.
If you’re not, take our advice and DO NOT check the expand interest box when launching campaigns, especially if they’re to cold traffic (people who have never heard of you before).
2. Facebook Targeting Expansion Could Be Used for Scaling
I wouldn’t recommend checking the expand interest box when launching campaigns to cold traffic, BUT I do believe there could be a use for this box when scaling your ads.
Once a campaign has run to the point of fatigue (your frequency is high) clicking this button could allow you to scale and show your ads to more people that are most like the ones who have already taken your desired action. 
This box could allow you to broaden your targeting and to quit showing your ad to the same users over and over.
We are in the process of testing this strategy and will report back.
(RELATED: The Ultimate Guide to Scaling Paid Traffic Campaigns)
3. This Feature Will Get Better
While the results aren’t very promising for Facebook’s expanded interest box, I do believe we will see improvements over time.
Facebook’s algorithm is getting smarter every day. As the platform gathers more data and feedback on this feature, they will continue to improve it. My guess is that we will test this again in six months and see very different results.
But for now, leave the box unchecked… our tests show that you’ll see better results for your Facebook ad campaigns.
