Microsoft Rewards, previously known as Bing Rewards, gives you points for doing things like using Bing as your search engine, using EDGE and spending money at the Microsoft Store, something which happens if you buy digital Xbox One games.
In exchange for varying values of points, you can get some free stuff. You can redeem your points for things which include Sweepstakes for consoles and PC hardware, Groove Music Passes, 12 months of Xbox Live Gold subscription, Skype call credit, Amazon, Starbucks and GameStop gift cards and even donations to charities on your behalf.
Now, you can exchange your points for a Halo 5: Guardians REQ Pack for 3,100 points or 2,900 if you are a Gold Reward members. You can do this five times per account.
Halo 5: Guardians is available now for Xbox One.