Microsoft has a training program for retail store employees where for just a few dollars shipping you can earn free Microsoft Game titles for the XBOX (as well as free Microsoft PC software).

Once you sign up, they have training modules on their products that you can complete and at the end there is quick quiz. As you progress and complete the quiz's on their site, you receive points. Once you establish enough points, you can redeem them for free (just pay shipping) Microsoft software.

Microsoft Retail Training