Leaderboard support for local and global score comparison of progress in the game to promote a competitive enviroment for users to return.
Support for game invitations to play the game which helps the promotion of the game as well as return of players to the game.
Achivement System encourages the tailoring of specific goals for the player to acheive or aim to accomplish for the rewards that can be obtained.
Purchases to unlock especial content for or collectables that will separate players from others. Helping promote your game and keep it growing.