Meta did not respond to comment on the change in the weight of a one-day conversion window.

More incrementality and comparison with third parties

Besides the change to conversion windows, Meta is also making changes that show advertisers how many users took an action on an ad as a result of specifically seeing it on one of Meta’s platforms.

When Apple deprecated mobile identifiers in 2021, Meta had less data about who to target and how to measure whether those ads worked, causing ad performance to plummet.

In the past three years, Meta has solved this problem with AI which has improved performance, but advertisers worry the campaign reports Meta gives are more modeling than reality. They worry that the modeling makes Meta ads look like they perform better than they do.

Meta’s updates to its ad systems could alleviate those concerns.

Meta is now allowing advertisers to optimize for incremental conversions. A user who scrolled past a Meta ad for shoes might have bought the shoes anyway, but an incremental conversion would represent a customer brought in uniquely by the ad.

Meta calculates incrementality by comparing conversions from a group of people exposed to an ad to conversions from people who didn’t see any advertisement. The difference between the two helps figure out how many conversions were incremental.

Incrementality testing is a big reason why ad buyers have been turning to third-party measurement solutions like Rockerbox, TripleWhale, and Measured.

Another reason advertisers have turned to these vendors is to figure out which platform is most responsible for a sale. A user could have seen an ad for a product on Meta, TikTok, and Google before making a purchase, and each platform could be taking credit for driving the sale.

Now, advertisers can connect these third parties with Meta, starting with Google Analytics and Northbeam. Meta will soon expand similar tools to Adobe and Triple Whale. Meta will use this data in campaign optimization to improve its relative campaign performance.

“One of the biggest criticisms of Meta, specifically from performance advertisers, is that its in-platform attribution is wildly inaccurate compared to a third party ‘source of truth,’ ” D’Altorio said. “These changes will better calibrate their ad system to close that gap.”

Meta has already started to use some preliminary third-party data from early tests with advertisers to make changes to its overall advertising algorithm.

“We would like our system to be customized to deliver [advertisers’] specific way they think their media performs. We’re not there yet,” Fred Leach, vp of product management, told ADWEEK. “That’s ultimately what the connection with third-party analytics tools should allow us to do. But right now, we’ve gained enough aggregate learning where we can tune the system to where, on average, we believe it’s going to deliver more value for advertisers”

Correction: The headline on an earlier version of this article misstated that Meta was changing how conversions are measured. The headline has been updated to reflect that Meta has changed how its algorithm is optimized. This article has been updated to clarify that the change affects campaigns only where a marketer wants someone to make a purchase, not for app download conversions. And to reflect that Meta will now give more weight to the conversions occurring one day from when a user first clicks.