A:Answer On this listing, you can click that blue bar that says it's eligible, and you will be brought to the page where it both lists, and contains the terms of preorder.
From the bottom of said page:
"For each qualified purchase, receive 500 My Best Buy points (worth $10 in reward certificates) credited to account approximately 15–20 days after street date or store pickup. Limit one award per member per title."
Basically, once the game is outside the standard return period, the points will automatically be deposited into the MBB account used to preorder and purchase the games listed.