It is easy to earn with Bing rewards. Simply create a free account and set Bing as your search engine and earn credits by search on your PC and/or mobile phone. Status upgrades allow you to earn even faster. Great site to earn gift cards such as amazon, target toys r us and more.
* Update Bing Rewards is currently going through a transitional period and will become Microsoft Rewards. based off the info presented so far looks like it will continue to offer the same rewards but the point system might be changed a little. Stay tuned for more updates.