Because of Apple’s IDFA in-app data tracking process, Facebook taken to warning advertisers of some of the major impacts that will occur. Unfortunately, the ones to see the biggest losses due to these new prompts are its Audience Network partners.
There will be new in-app popup alerts coming out of the process, asking users to opt-in to data tracking within every individual app, and due this, it’s easy to expect many users will end up opting-out. If that’s the case, that means there will be a significant amount of data lost for ad targeting.
Source – Social Media Today