Samsung has announced a US only promotion, that runs until January 6, which will give you a $50 Google Play store credit. All you have to do it go to the promo page (link), enter your information (IMEI, name, address, email, etc).

The offer is open to US Samsung Galaxy Note 3 only and is open to anyone who has already bought a device (until Jan 6).

Note: They do check the IMEI allocation and will block all non-US IMEI numbers from the promo( even if you fake the address).