This transparency tool, designed to give users more control over their data, will be rolling out in the coming months. How will it affect advertisers? Once the tool is live, users will be able to disconnect their off-Facebook activity from their profile, and in doing so they remove advertisers ability to target the users (at least until they return again). This will without a doubt change the playing field and likely change the way advertisers plan and target their audiences. We expect a much higher reliance on controllable sources like email lists.