[quote name='tossin']As far as I know, it does as long as it's not past the expiration date. But if it disappears regardless, you can probably always shoot Amazon a complaint.
Also, be aware that some promotional credit is one-time use only, so if you don't use all $20 at once, it might be gone. Usually that's for credit that can ONLY be used for future game purchases, but in this case the credit seems general, so I don't think you need to worry about this.[/QUOTE]
I have the general promo credit, so I don't think I have to worry about using it all at once (although I will be doing so, since it's only $15). I'm just going pay with my credit card and then change the method of payment when I'm 100% sure I want to keep the order. I have a month to make up my mind.