PetVille Pet Cash + Diamond Disco collection coming soon

Pet Cash will soon be coming to PetVille, and every pet will start out with a certain amount of cash and then have the chance to earn more by playing the game. There's already coins in PetVille, and Pet Cash will be harder to come by -- and be required to buy extra fancy clothes and household items for your pets.

Games such as FarmVille and Pet Society have similar two-pronged virtual payment system -- coins, which can be earned by playing the game, and cash, which usually requires a player to plop down a credit card to purchase, which is then used to buy rare or "premium" items in a game.

Facebook game makers, of course, make a boatload of cash from players who purchase premium items, but players are often annoyed when premium items aren't so premium (e.g., the storage barns in FarmVille) or when premium items simply cost too much.

Most likely the Diamond Disco Collection, also set to arrive this week, will include items that can be purchased for Pet Cash only.