Two startups are trying to do for e-books what Netflix does for movies.

Oyster and Scribd let you read as many books as you want for a monthly price – $10 for Oyster and $9 for Scribd.

I was worried about their limited book selections. But I found plenty to read in no time, and I found myself reading more than I normally would. Just don’t think it’ll be the same as walking into a library and finding just about any book you want.

THE SELECTION

I checked several titles from my wish list and asked colleagues for other suggestions, including a few for kids or in foreign languages. Of the 75 I checked, Oyster had 17 and Scribd had 16. For some popular novels, such as The Hunger Games series and A Fault in Our Stars, I got readers’ guides and other companions, but not the actual books.

Both services have selected titles from Simon & Schuster, HarperCollins and lots of smaller publishers, but other major U.S. publishers – Hachette, Macmillan and Penguin Random House – remain holdouts. And even when there’s a deal with a publisher, newer books tend to be excluded.

Avid readers won’t be bored, though. When I signed up, Scribd asked about the types of books I like. Oyster didn’t but still made good recommendations based on what other subscribers are reading.

I quickly found about two dozen books between the two services. Each time I added a title, I got recommendations for more. I just finished books on lobster populations and the Ben & Jerry’s ice cream company. I’m now reading about Lance Armstrong and the doping scandal – another book I wouldn’t have known about if it hadn’t popped up on Scribd.

In that sense, both services are much like Netflix. Netflix’s streaming selection looks poor when you are searching for a specific title, but Netflix is smart enough to recommend enough movies to keep you paying $8 or $9 a month.

There are enough books to keep you busy for months or years. Oyster has more than 500,000 titles, while Scribd has more than 400,000.

THE APPS

Neither Oyster nor Scribd works on dedicated e-readers such as Amazon’s Kindle Paperwhite. Rather, you need a device that lets you install apps.

Both work on iPhones, iPads and Android devices, including Kindle Fire tablets. Oyster also works on Nook tablets, while Scribd has apps for Windows devices. Only Scribd lets you read on Web browsers on personal computers, though Oyster plans to add that soon.

Apps for both services offer features typical for e-books. You can start a book on one device and pick up where you left off on another, though I’ve often run into syncing problems with both. You can see where you are in a book, change text size and add notes. The options aren’t as extensive as what I’m used to with Kindle devices and apps, though.

Oyster lets you store up to 10 books per device to take with you on the road, while Scribd lets you save up to 20 books. Both services permit reading on up to six devices.

Of the two, I like Oyster’s apps and e-book selection better, and it’s been adding features and device support quickly to catch up with Scribd. But it’s also $1 a month more.

THE BARGAIN

There are plenty of other ways to get e-books for free or for a set price. Check your local library for starters. If you have Amazon’s $99-a-year Prime membership, you can read an e-book for free each month if you also have a Kindle device or the upcoming Fire phone, though you’re not offered everything that Amazon makes available for purchase.

If you read just one book a month, you’re probably better off buying it – typically for less than the monthly subscription price. You own the book outright that way, and the selection is better. With Oyster and Scribd, access to the books ends once you cancel your subscription, which you can do anytime.

If you read two or three books a month, consider a discount e-book service. With Entitle, for instance, you get two e-books a month for $10, and you own them forever.

Oyster and Scribd are good if you read three or more books, or if you like to sample – start several books before deciding which ones interest you enough to finish.

Both services offer the first month free so you can see for yourself how much you can read.