i heard the rewards program can help me purchase games that i would like to have

If you haven't signed up already, you would need to sign up at http://rewards.xbox.com in order to start earning credits. In order to receive credits, you would need to complete the offers listed on the Missions page of the site. Credits are deposited into
your account as currency you can use to make purchases after you have at least 5,000 credits pending.

It depends on which Rewards program you're referring to.

For the Xbox Rewards program, you only receive credits for microsoftstore.com purchases if there is a specific offer for them. For help with that program, you would need to post in the Xbox Rewards Questions forum.

For the Microsoft Rewards program I believe it also depends on what offers they are running at the time. For assistance with that program, you would have to contact their customer support. Their contact can be found on their redemption page.

Free is free. Why would you buy games just for the rewards program? I can remember when games had no achievements or perks besides well, Playing the Game and having fun. You Don't have to join the rewards program or purchase games. (Gold is optional
along with the Rewards) GOOD LUCK!!!

Hi,

I would like to recommend you the Microsoft Rewards program.

With Rewards points you can purchase games, add-ons and GPU subs. If you have a family account, then you can share the points with the major account.

And the money you save for this account could be used to purchase a second GPU sub !

For help with the Microsoft Rewards program, you would need to contact their customer support via their redemption page. They are not the same as the Xbox Rewards program. I do believe for that offer, the game had to be purchased after release. Preorders
are not eligible.