Review: New Amazon service offers unlimited e-books, but pricey given limited selection

Amazon's new "unlimited" e-book service lets you read 600,000 books. That sounds like more than you'll ever read, but I found myself struggling to find the books I wanted.

It turns out that the library of 600,000 is bit like a small bookstore with a few current titles such as "The Hunger Games," attached to a block-sized bargain bin of obscure stuff mixed with "Robinson Crusoe" and other classics that are in the public domain and available for free online anyway.

Startups Scribd and Oyster both offer better value for avid readers of popular books.

Though Oyster has only 500,000 books and Scribd has 400,000, both offer extensive libraries from two of the largest publishers, HarperCollins and Simon & Schuster. Kindle Unlimited doesn't.

Kindle Unlimited and Oyster both cost $10 a month, while Scribd goes for $9. All three offer the first month free.

Weeks ago, as I was reviewing Scribd and Oyster, I asked colleagues to suggest books that ought to be on such services. I also added titles from my own wish list. Of the 75 I checked, Oyster had 17 and Scribd had 16. That's not a lot. I got even fewer with Kindle Unlimited — six matches, plus one that's free for everyone.

But through Amazon's $99-per-year Prime program, I could already read four of those six books for free on Kindle devices. Only "Silent Spring" by Rachel Carson and "Flash Boys" by Michael Lewis require the Kindle Unlimited subscription.

Under Prime, however, I can read only one book a month. Kindle Unlimited lets you download 10 books at a time on up to six devices. Those devices don't have to be Amazon devices, as Prime requires.

Kindle Unlimited also beats its rivals in several ways:

— It has 2,000 audiobooks from Amazon's Audible business. They're synchronized to the corresponding books, so if you need to break off reading to drive, you can have the audiobook play instead, starting where you left off reading.

— For the first three months of your subscription, you can choose one additional audiobook per month from Audible's larger catalog. You get to keep these books even if you cancel your subscription.

— Only Kindle Unlimited permits reading on Kindle e-readers such as the Paperwhite. I personally prefer reading without distractions from email and Facebook.

— Kindle apps for phones and tablets are more sophisticated than the competition. For instance, you get an estimate of how much time you need to finish the chapter or the book, based on your personal reading speed. Oyster does that only for the chapter, while Scribd offers neither.

— Kindle apps are available for a greater range of devices. Oyster works on iPhones, iPads and Android devices. Scribd supports those, plus Macs and Windows devices. Kindle does all that, plus webOS and BlackBerry devices.

Back in 2011, Amazon began making a selection of movies and TV episodes available for free to Prime members. At the time, the free service had 5,000 videos — but few that I actually wanted to watch. That's been expanded to more than 40,000 and includes decent movies and shows. Amazon has even commissioned original shows for Prime, including the John Goodman comedy "Alpha House."

Kindle Unlimited will have to follow the same path and expand its library to be useful for most people.

With any of these services, you need to be reading three or more books a month to make it worth the subscription. Otherwise, buying the e-book through Amazon or a discount service such as Entitle is more economical. The limited selection makes it tougher to find those three books a month, especially for those who already get a book a month for free through Prime.