Not for books but too easy to pass up. I didn't have a Twitter account, signed up for this deal the clicked the button on the Amazon page and got my $5. Offer good thru 9/2, credit expires 10/31.
Amazon is offering $5 Amazon Video on Demand Credit for Free when you follow the instructions below.
Click here
Click on the "Tweet and Get $5" button
You will be prompted to log in to connect your Twitter account
Click on the "Allow" button
You will receive the following message at the end: "We have successfully applied a $5 credit to your Amazon.com account, good for movies and TV shows at Amazon Video On Demand."Optional: Follow us on Twitter