Oyster, the e-book subscription service launched in 2013, is adding a retail component to its services. Oyster is now offering more than a million e-books for sale, including titles from all of the Big Five publishers.

Consumers can now choose to subscribe to Oyster for $9.95 a month with unlimited access to more than a million titles, or purchase individual titles directly via the Oyster app and website. The Oyster e-book store is also available to both Oyster subscribers and non-subscribers, and will offer frontlist titles and pre-ordering. While the e-book store will sell titles from all Big Five publishers—Penguin Random House, HarperCollins, Simon & Schuster, and Hachette—only S&S, Macmillan and HarperCollins include their titles in the subscription service.

The retail service will make titles by such authors as Gillian Flynn, James Patterson, Donna Tartt and John Green—authors from publishers who do not participate in Oyster’s subscription side—available for sale via Oyster for the first time. An author like Stephen King, who has some of his some titles available via subscription, will now have his full title list available on Oyster, either through the subscription service or the e-book store.

Oyster is positioned as book discovery platform, and subscribers will see both subscription and for-pay titles—subscription-only titles are clearly labeled "unlimited'—in their recommendations. Titles will also be on sale via The Oyster Review, the subscription service’s online literary review and recommendation platform.

In an interview at the Oyster offices in Manhattan, Oyster CEO Eric Stromberg said the new e-book store will be “competitively priced” with other e-book retailers. Oyster has struck retail terms on both the agency model and the wholesale model, depending on the publisher. Stromberg said that while “it’s harder to discount today, there will be some discounting on a publisher-by-publisher basis.”

Asked if Oyster was profitable, Stromberg said he “can’t comment on financials,” but added that Oyster’s publishers and authors “are happy with our business model." He also said the company is "thriving.” Oyster is currently available only to North American consumers, but Stromberg said that "expanding internationally is definitely a focus for us in 2015."

Speaking to growth, Stromberg noted that the number of Oyster subscribers grew 20% every month in 2014. The service has seen a notable jump in reads, as well. In 2013 Oyster reported its users read 8 million pages read per month; in 2014 that number jumped to over 100 million pages read per month. Oyster's subscription service now has titles from more than 1,600 publishers—though only S&S, Macmillan and HarperCollins from the Big Five—and offers more than a million titles to subscribers. Originally focused on backlist, Oyster now offers frontlist titles. Stromberg has said that 20% of the titles read on Oyster are less than a year old.

The decision to add a retail component to the site, Stromberg said, was driven by “ongoing conversations with our partners.” The e-book store, he added, now enables Oyster users to have reading and retail options “all in one place.”

“We want to be synonymous with books, so we’re building a bookstore for mobile devices and tablets that offers easy browsing and enjoyable discovery,” Stromberg said.

Correction: Three of the Big Five offer their titles via the subscription service, Macmillan was left out in an earlier version of this story. Also Oyster subscribers grew 20% each month in 2014, not just for the year.