Oyster, an online service that lets you read as many books as you have time for a monthly fee of $10, has opened a bookstore where ebooks can be downloaded for offline reading. Oyster doesn’t tell how many books it has for sale, but proudly states that the big five publishers in the US (Hachette, HarperCollins, Macmillan, Penguin Random House and Simon & Schuster) among many others are on board.

Oyster’s bookstore is a convenient place to shop for existing subscription customers who occasionally want to purchase a book in order to make sure it is always accessible. For example, travel guidebooks fall into this category because you can’t assume you are connected to the Internet when on the road. Another thing is if Oyster can (or wants to) compete against Amazon, Apple iBooks, Google Play Books or Kobo purely as an ebook store.

Other ebook subscription services that let you read books for a low monthly fee are, for instance, 24 Symbols and Scribd.