GMG is an authorized EA/Origin retailer. Keys are instantly displayed during checkout (and emailed to you). Just add to your Origin client and start downloading the 8.57GB download!
If you don't see the $12 off when you enter the coupon at GMG, click on CONTINUE and you should see the price changed to $48 before you checkout. This is a bug that seems to appear on certain browsers.
The Sims 4 Digital Deluxe Edition includes:
In order to claim the $10 Rewards, you'll need to be a My Best Buy member, sign up for free here. If you're an Unlocked member, you'll get 20% off in addition to the $10 certificate.
In addition to The Sims 4 base game, the Limited Edition will also include the "Life of the Party" DLC as a pre-order bonus. This is the cheapest price we've found for The Sims 4 from a large digital gaming retailer.