According to The Wall Street Journal, Amazon will soon launch a subscription-based book service, charging a monthly fee for access to a library of e-books.

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To Amazon, the devices are just delivery channels for more content and the e-reader push towards lower and lower price will allow the company to throw e-readers in with the delivery of a book or a large enough commitment to a content subscription.

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Major publishers are taking wildly different approaches to resolving the woes surrounding e-book lending at libraries: they're experimenting with both the short-yet-cheap subscription as well as an expensive option to pay only once for perpetual use.

ENGADGET: Macmillan tests selling e-books to libraries in two-year stretches