Amazon has come up with another “huh, interesting, I could see this working out” idea called Amazon Cash. As the name suggests, it's a way for you to turn cash into Amazon credit. While that might seem counterintuitive to some, I know there are people out there like yours truly who tend to spend cash in my pocket far faster than if I put it in the bank or have it as store credit.
Regardless, you should jump on it now since they're offering $10 in free Amazon credit! Simply generate a barcode by clicking the “Get Your Barcode” near the top left. Then either print it out or send it to your phone via text and visit a participating merchant like CVS, Gamestop, Cumberland Farms, Kum & Go, or Kwik Trip (there are more, plus new merchants will be added soon). You'll then pay $20 in cash and have the store scan your barcode, which will give you $20 Amazon credit PLUS a free $10 Amazon credit on top of that.
So in effect, you pay $20 in cash and get $30 in Amazon credit! The free $10 credit offer ends 7/31/17 and you have until 8/31/17 to redeem your credit.