Games inside the Playphone Game Store may have virtual goods inside of the game that can be purchased.  These items include, but are not limited to, extra cash or additional lives inside of the game.  Many games will have a Store, Shop, or Get More icon that will display packages of items that can be purchased.  Once you select the desired package, you will be prompted to input your purchase key or apply your Playcredits balance.  After a good has been purchased, the item will be sent to your account and you will be able to use the item almost instantaneously.