Previously, publishers of periodicals received a mere 30% of each title they sold through the Kindle Store.
To qualify for the more generous revenue split, publishers are required to make their content available on all Kindle devices and applications -- including its e-reader, desktop application, and mobile apps for iPhone, Android and BlackBerry -- and in all countries for which that publisher has rights.
The new terms do not apply to blog publishers "because existing terms are generally more advantageous to them," Amazon said in a statement.
Lately, publishers have been focusing their efforts on developing applications for tablets with more robust operating systems than the Kindle, such as the iPad and Samsung's forthcoming Galaxy Tab device. With a substantially bigger revenue cut to be had, Amazon no doubt hopes that publishers will give more attention to developing for its platform in the future.