Amazon also offers the Kindle Unlimited subscription service, which offers unlimited access to a curated library consisting of over four million books and thousands of audiobooks and magazines. Nook ...

Nook users have access to the Nook Books store from Barnes & Noble. Of the two competing stores, Amazon's is more extensive ...

Barnes and Noble is going head-to-head with the Kindle Fire with its new 7-inch Android tablet, but can it compete with Amazon's digital store?