Google Play Books is running a rare promotion where if you spend over $5 on an e-book you will receive $5 in credit. The credit that you earn can only be applied to eligible book titles with an on store price of over $5.01 or more before tax is imposed. Google has created a special landing page on their bookstore and it has a revolving list of hundreds of titles from major publishers.
The one thing I like about this promotion is that all of the books on the list have been severely discounted. Titles that normally retail for $17 now cost only $9.99, but some of the more mainstream books like Princess Diaries by Carrie Fisher or Cross the line by James Patterson have not been marked down.
The $5 credit on any book that costs $5 or more is a limited time promotion. It starts today and will expire on March 31, 2017.