Amazon is testing an ebook and audiobook subscription service called “Kindle Unlimited” that offers “unlimited access to over 600,000 titles and thousands of audiobooks on any device for just $9.99 a month.” Most of the test pages were pulled down Wednesday after some users on the Kindle Boards noticed them, but they are still available through Google Cache and some are still live on Amazon’s site. Amazon’s service, which has been rumored for a couple of months, would compete with existing ebook subscription services Scribd and Oyster. Publishers Lunch reported last month that Amazon was speaking to U.S. publishers about participating in such a service. One page, still active at the time of this post and titled “KU Test,” shows 638,416 available titles, and you can browse through them.