Go to this page and follow the instructions to get a free $2 Amazon Instant Video credit.
You’ll have to share on Facebook to get it, but it’s all set up and you actually just fill in the blank and click on share to do it.
Don’t forget to use it, these credits always expire pretty quickly.
Here’s some of the fine print: Upon completion of the “Share & Claim” action, a $2 Amazon Instant Video credit will be automatically applied to your Amazon account. Promotional credits must be redeemed by 11:59 PM PST on May 29, 2012.