Works with new accounts (Just tested it) as long as you click on this link https://www.amazon.com/b?&=&node=14730500011
Says they will send you a redemption code so should be able to apply to any amazon account after you receive it
Terms and Conditions
- This is a limited time offer. This offer is valid from 12:01 a.m. (PT) on Aug 19, 2016, until the earlier of 11:59 p.m. (PT) Aug 25, 2016, or when all Amazon.com Gift Cards are claimed.
- This offer is only available to customers who land on this exclusive offer page from an email or advertisement delivered directly from Amazon.
- Recipients will receive their Amazon.com Gift Cards within 7 -10 days after that first sign in.
- You will receive an e-mail from Amazon that confirms delivery of the Amazon.com Gift Card and its dollar amount. The e-mail will also provide instructions on how - to use the Amazon.com Gift Card.
- This offer only applies to the Amazon App and Underground App and not any other app created or distributed by Amazon or its affiliates. Learn more about Amazon apps.
- Offer limited to one Gift Card per eligible account.
- Amazon.com Gift Cards never expire. For complete Gift Card Terms & Conditions, visit www.amazon.com/gc-legal.
- Offer is non-transferable and may not be resold.
- Amazon reserves the right to modify or cancel the offer at any time.
- If you violate any of these terms, the offer will be invalid.
interesting.. wonder if you can get the $5 off $10 with the Amazon app referral deal then a further $5 with the underground app from this one.