(AP) -- Amazon.com Inc. is giving a hint about how many people are using the Kindle and related apps.
The Kindle e-reader starts at $139 for a version that can wirelessly download content over Wi-Fi, but Amazon also offers a number of free applications that can be used to read Kindle books on gadgets such as laptops, tablet computers and smart phones.
The online retailer said millions are reading Kindle books on the dedicated e-reader and on free apps. This still doesn't give an indication of how many people have bought the Kindle - something which the Seattle-based company has never given precise details about. But it does make it clear that many people are flocking to Amazon's device and Kindle software.
Meanwhile, Amazon has begun allowing customers to give its Kindle e-books to others, even if they don't have the Kindle electronic reader. The recipient simply needs an e-mail address. There are currently more than 725,000 books in Amazon.com Inc.'s Kindle Store.
Explore further: Amazon releasing Kindle software for Android