You can earn the storage by signing up for Bing Rewards, a program that gives you credits every time they use Microsoft's search engine. Microsoft said users who earn 100 credits can redeem them for the free storage with OneDrive, the company's cloud service that was formerly known as SkyDrive.
You can earn 20 credits when they sign up for Bing Rewards. You are also awarded 15 credits every day that you use the Microsoft search engine. If you have already a Bing Rewards account, you can accumulate 100 credits in seven days.