I have got an email for the $7 amazon video credit today. This must be an account specific. YMMV.
email subject line : Here's a $7 Amazon Video credit just for you
Dear Amazon.com Customer,
'Tis the season for giving. Amazon Video has a $7 credit for you and your loved ones to enjoy together. Find the perfect movie or TV show with this gift of entertainment. If you're looking for a deal, we have digital movies and TV shows on sale now.
To redeem your $7 Amazon Video credit, follow the steps below:
Click the button below. If you're not already signed in, sign in to your Amazon account when prompted.
The credit will automatically be applied to your account after signing in. You will see a page confirming the offer has been applied to your account, and then you will be redirected to Amazon Video.
Choose an eligible movie or TV show to rent or buy.
The credit will automatically be applied to your selection and the discounted price will be shown in Your Order History.
You must redeem and use your credit by December 31st. *Terms and Conditions apply.