They found that people who regularly read electronic books before lights out sleep for fewer hours.

Seattle - Amazon is rolling out a new subscription service for Kindle devices that will allow users unlimited access to thousands of books and audiobooks for $9.99 (about R100) a month.

The company said that the Kindle Unlimited service will give users the ability to read as much as they want from more than 600 000 Kindle books such as The Hunger Games and Diary Of A Wimpy Kid.

They can also listen as much as they want to thousands of Audible audiobooks, including Water For Elephants.

Subscribers will get a free three-month Audible membership.

A Kindle Unlimited logo will be attached to eligible titles. The subscription service is available beginning Friday and is accessible via Kindle devices or with Amazon's free Kindle reading apps.

A free 30-day trial can be accessed at - Sapa-AP