Amazon can put another notch in their ebook “library” bedpost. As of this writing, there are now 200,433 ebook titles in the list of ebooks in the Kindle Owners’ Lending Library.

Amazon’s Lending Library launched under a year ago on November 3, 2011. It allows anyone that owns a Kindle and that subscribes to Amazon Prime for $79 per year to be able to borrow one ebook from the library for free each month. There is no such thing as a limited number of copies and there are no wait lists. If you want an ebook that’s in the list you simply click a button and boom you’ve got your borrowed ebook for free. Once the next month starts you can get another one for free.

This one ebook per month limitation has created an interesting situation where people will borrow one ebook from an author for free and then buy other ebooks from the same author. Book publishers could probably use this same model as a way to promote their ebooks through public libraries.

The lending program is incredibly popular and new titles are being added constantly. It took 96 days for Amazon to get the first 100,000 ebooks in the library. Over the next 95 days, another 50,000 titles were added. To reach 200,000 ebooks took 113 days. So it looks like the growth rate has stabilized at roughly 50,000 new ebooks per quarter.

That is an absolutely stunning number of titles. To put that number in perspective, if you combine all the ebooks at the New York Public Library, Los Angeles Public Library, Boston Public Library and Seattle Public Library you will arrive at a little over 100,000 ebooks. The Kindle Owners’ Lending Library has almost twice the number of ebook titles as some of the largest public libraries combined.

Of course the comparison is a little unfair since the book publishers aren’t actually selling ebooks to public libraries. Only two of the big six book publishers allow libraries to buy their ebooks because they’re afraid that someone that borrows an ebook for free will be unwilling to pay for the same ebook. Amazon continues to prove them wrong every day with their ebook “library”.

Amazon’s Kindle Owners’ Lending Library will continue to grow at an astounding pace. The question is will libraries be able to get ebooks from book publishers so that they can grow too?