User blog comment:PFC Arkalis/Update: BF3 Pre-Order Bonuses and Open Beta FAQ announced/@comment-24476373-20110813022417/@comment-70.30.55.73-20110813234734

Some betas you need another game to have that contains a key code. Some require you to have an upgraded membership like PS Plus. Some you need to find key code on the internet or win one at a contest. And some are just plain free.