In a baffling move, Microsoft plans to reduce its free storage from 15GB to 5GB. Of course, the immediate response wasn’t positive. So, Microsoft is backtracking somewhat with a new promotion that promises users they can keep their 15GB if they want it. And if you use Camera Roll Bonus, that is also another 15GB. But you have to opt-in before the end of January 2016. You can claim your storage from this link.
Source: Droid Life