Credits can be purchased via credit card, Paypal, mobile phone or through the gift cards currently being sold in Target retail stores around the U.S. Over 200 games and applications on Facebook currently use Facebook Credits system, according to Liu, spanning over 75 developers.

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If you have a GSM phone, you can get cheaper service by swapping out a small card located in the back of your phone and replacing it with a local version. (This won't work on CDMA phones, as they don't have these cards.) Called "SIM" cards, they're sold in phone shops and can be purchased prepaid.

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