In addition to purchasing credits within Facebook, there are a number of online and offline channels for earning or buying Facebook Credits. These include the following.
Gift cards - In the U.S., Target, Walmart, Best Buy, Radio Shack, GameStop, and Safeway sell Facebook credit gift cards in their stores. Facebook Credits gift cards are sold in Tesco and Game shops in the U.K. Facebook Credits gift cards are also sold in over 500,000 outlets in five Southeast Asian countries, India, Australia, and New Zealand.
Rixty lets users get Facebook Credits by buying a prepaid Rixty giftcard with coins or cash at stores and then converting it to Facebook credits.
Shopkick allows users to earn Facebook credits by checking in to stores with an iPhone or Android application.
ifeelgoods enables online retailers to offer Facebook Credits as incentives for making purchases, signing up for e-mail newsletters, and other actions.
AppDog awards users with an Apple or Android mobile device with free Facebook Credits in exchange for downloading apps. Downloaded apps can be free or paid.
Bing Rewards Preview allows you to obtain Facebook credits