Attached is a link to the pro days flyer. Just went into the store to do this.
Basically, GameStop is offering a couple promotions around its membership program.
Step 1: By signing up or renewing, you get 10,000 points (worth $10).
Step 2: Preorder Cyberpunk 2077 (also works with Watchdogs) and pay in full. As long as this is a $60+ purchase and you are a pro member, they give you a $10 coupon.
Step 3: When you pickup Cyberpunk 2077, you will get $20 in gamecoin as long as it's picked up launch week.
So in summary, you pay $15 for a power up membership and $60 for the preorder game, and you get back $40 of GameStop credit.
The membership also gives you $5 a month to spend on stuff, so there's value there as well.