Cash is the premium currency in WWE Champions and when you have earned enough of it you will be able to tap the 'Loot' icon and and buy 'Premium Superstars' in the shop. For 400 Cash you will be able to purchase one poster of up to 2-Star Gold rarity, 4000 Cash gets you 10 and 10,000 Cash will earn you 30. There is also an in-game store where you can spend real money on the various offers that are available.