Well I was going to write this smart ass reply (obviously exaggerated):

This is Gamestop. The amount of store credit you get for returning a game probably isn't even enough to buy a pack of gum ... and if it is ... well guess what Gamestop doesn't even carry that! 

...And then I realized that after reading the whole OP they actually give you all your money as credit (minus tax)

That's actually a pretty good deal. Almost makes me want to purchase Days Gone just to try it.

No, it's just nice to have an insurance policy.

I would never abuse it like that but it's a great policy. The single biggest issue for me with console gaming is the fact that I can't try out games and see if I like it first before investing $60 into it. Steam lets me refund after 2 hours which isn't enough sometimes but it's better than nothing. Either way on PC I have other options to really try a game before I buy it. For consoles I would buy used and try it like that then get the digital version.

 It's been a policy at EB Games Australia for ages and unlike the 2 offered here its 7 days, also believe it's for cash and not store credit.

I always think I will use this but rarely do.

I don't have a major issue with EB Games in general, but once or twice when I have done this I got a fair chunk of 'put the money towards XYZ' pushback.