Apple made accessing a devices IDFA (device fingerprint) a permissioned resource. Needless to say it is not a popular permission to grant.
Cross-app activity can't be tracked without this permission. So if you see an ad for a product on facebook, then you pop over to Safari, search for the product, and purchase it, facebook can't attribute that sale to that ad.
The consequence of this is that goal attribution (like sales) for ads is harder, so FBs models can't learn as well who would be interested in the products. You'll see less relevant ads and companies' cost of customer acquisition will go up.
It's easy to imagine a world with less effective ad targeting since most media doesn't have effective targeting. Think pharmaceutical commercials on TV.
My own bias: I run a niche D2C brand whose business model got wrecked by this change!
Cross-app activity can't be tracked without this permission. So if you see an ad for a product on facebook, then you pop over to Safari, search for the product, and purchase it, facebook can't attribute that sale to that ad.
The consequence of this is that goal attribution (like sales) for ads is harder, so FBs models can't learn as well who would be interested in the products. You'll see less relevant ads and companies' cost of customer acquisition will go up.
It's easy to imagine a world with less effective ad targeting since most media doesn't have effective targeting. Think pharmaceutical commercials on TV.
My own bias: I run a niche D2C brand whose business model got wrecked by this change!