Facebook has released the getBalance API call as an incentive to game developers who use Facebook Credits as their exclusive premium in-game currency. The call lets developers determine the Facebook Credits balance of any of their users. This allows them to identify high rollers with a large balance of Credits and dynamically price virtual goods to increase purchase probability or profit margin, improving monetization.
Starting July 1st, all Facebook games must process payments exclusively through Facebook Credits, Facebook’s virtual currency. Developers can either use Credits as their payment method, allowing users to purchase a game’s proprietary premium in-game currency with Credits, or use Credits as their premium currency. Facebook wants developers to use Credits as their in-game currency (PDF) because it removes an extra step from the spending flow, as Credits as a payment method requires users to buy to credits to buy premium currency to buy virtual goods.