Recent case study’s results

Campaign objective: Reach
Placements: Facebook, Instagram
Frequency cap: 3 impressions every 7 days
Test duration: 7 weeks
Audience retention: last 90 days

Users in the audience at the beginning of the test (accd. to GA data): 13,000
Additional new users during the 7 weeks of the experiment (accd. to GA data): 6,400
Total: 19,400 users were eligible to see the remarketing ad

Facebook matched (est. audience size): 2,100 – 2,500 (~11%…13%)

Facebook reached even a bit more than the estimated audience size:

 

If you expect users to buy from you from the retargeting campaign, you should factor in your typical CTR from Facebook Ads and your typical conversion rate from the retargeting campaign. Calculations may look as follows:

• Users eligible: 100 000
• Users reached: 15 000 (because you can reach up to 15%)
• Users clicked: 750 (if CTR=5%)
• Users bought: 75 (if CR = 10%)

So, if you have a base of 100,000 users for retargeting, you can expect around 75 sales. Of course, your CTR may be higher or lower than 5%, CR may be higher or lower than 10%. I’ve just taken typical numbers.

The match rate also depends on the audience. In some industries, you can reach a bit higher % of users, for some – a bit lower. But 10%…15% is a current benchmark.

Conclusions

Facebook is still good at reaching the matched audience but it’s not that great with matching website visitors anymore.

You can increase the match rate (so, expand the reach) if you deliver your content on Meta properties, such as videos, messengers or instant experience – match rate is close to 100%. Or, by providing Facebook with the 1st party data about your customers, such as phone numbers and emails.

This is especially helpful for reaching leads as their number is usually much smaller than the number of website visitors and their probability of making a purchase is much higher.

Even though Facebook doesn’t provide audience size for customer lists, you can see an approximate match rate in the offline uploads section.

To increase the probability of reaching your website visitor with retargeting, you can also use RTB platforms such as AdRoll, Criteo, etc. They cover many more placements than if you’d retarget on Facebook and/or Google solely.