This week, Facebook rolled out its “conversion lift measurement” worldwide. It aims to tell advertisers the number of people who saw an ad on Facebook and then made a purchase either in store or online. Facebook will compare that metric to people who may have made a purchase without seeing the ad.
How is Facebook able to do this? It’s a bit complicated. Advertising Age explains:
The company takes the list of people who were shown the ad on Facebook. Then it compares that list with a list from the advertiser of people who converted in some way, such as purchasing a product from the advertiser’s brick-and-mortar store or adding it to an online shopping cart.
For Facebook to track an advertiser’s online sales, the advertiser must place a piece of code on its site that lets the company see when a Facebook user visits their site and performs a certain action. The advertiser tells Facebook what actions to look for — like whether someone adds a product to their shopping cart or buys the product — and then Facebook marks the people who take those actions.