Amazon testing e-book subscription service

In an effort to boost flattening e-book sales Amazon announced its testing a e-book subscription service for under $10. The publishing house / retailer will offer Kindle users access to 600,000 e-books and thousands for audiobooks for $9.99 per month.

Many titles from Amazon's own publishing imprints are offered, but none of the big-5 publishers appear to be participating in Amazon’s offer.

That said, Simon & Schuster and HarperCollins have made e-books available for similar services from Scribd and Oyster, charging $9 per month and $10 per month, respectively.

Industry trade group AAP estimates that e-book sales were roughly flat in 2013 at $3 billion in the U.S. They made up a little over one-fifth of total trade publishing revenue of $14.6 billion.