What bonuses does the client's authorization with the help of facebook give to the developer?

Question

Android

In mobile games, authorization using facebook is increasingly practiced.
Does this type of authorization give any bonuses to the developer, except for access to friends and personal information?

Answer 1

Friends see each other's progress in the game and compete with each other.
You can ask friends to unlock something in the game.
You can challenge your friends to a duel.
You can post screenshots to the feed.
You can collect email addresses for mailing.
You can adjust the game depending on the profile (by gender, by age).
Here are the basic examples of using facebook in a game application.