If your company has a Facebook app, and considering the increasing benefits you should strongly consider having one, it can now help to target your audience.
Brittany Darwell reports for Inside Facebook that the way users interact with your app can be used as a part of ‘Custom Audiences’, called App User IDs, to make a group to target. Users don’t even need to register through Facebook, or with an email or phone number.
Currently, App User IDs are only available for iOS developers, but the expansion to Android is expected soon.