Like its larger competition Oyster, Scribd, and 24Symbols, Inkbok offers readers the access to a catalog of titles for a flat monthly fee. For only $5 a month, readers can choose from a catalog of around 10,000 titles. There's also supposed to be an option to sign up and read the royalty-free (public domain?) catalog for free, but I don't see how that is accomplished.
Inkbok has a clean and well-designed website, and it is relatively easy to navigate whether you are searching by genre, author, or title. Readers can add titles to their shelf or reading list, and they can also post reviews. The selection is limited, and according to the FAQ readers are also limited to reading in their web browser. Inkbok is working on apps for Android, iPhone, and iPad but they are not ready yet.
In terms of paying authors, Inkbok has laid out their business plan, and it presents an interesting accounting problem. Inkbok is expecting various revenue streams to include membership fees, advertising, promotional fees, and affiliate fees. Rather than follow Scribd and Oyster's lead and pay authors based on the retail price, Inkbok plans to reserve 60% of revenue as a pool for paying authors. Each author will receive a share based on the number of times they are read.
Amazon uses a similar model for the Kindle Owner's Lending Library, though they work from a fixed fund.
It looks like 2014 is shaping up to be the year of the ebook subscriptions, with a couple major competitors (Scribd, Amazon) taking center stage, a number of middleweights (Oyster, 24Symbols) trying to move up, a couple outliers (Epic, Nuvem de Livros) pursuing niche markets, and newcomers like Inkbok coming out of the woodwork.