Microsoft has a Bing Rewards program set up to enable you to earn credits by simply using services available



From WP Central:

Previously, Bing Rewards was only possible through web browsers on a laptop or PC, but Microsoft has today announced that the program will hit Android and iOS today and soon Windows Phone.

For the time being the experience won't match what's possible on the PC, but the team at Microsoft will ensure that all Bing Rewards features will be available on mobiles over the next several months. By signing into your Bing Rewards account on your mobile device (again, Windows Phone support coming soon), you're immediately greeted with a new mobile optimised dashboard, displaying offers tailored for you.

  Microsoft launches Bing Rewards on iOS and Android; coming soon to Windows Phone