When Wattpad opened its online reading room in 2006, its catalog contained chiefly public-domain tear-jerkers such as "Sense and Sensibility."

It also invited budding Jane Austens to post their own oeuvres.

Readers, particularly young women, flocked to the site. It now draws 70 million monthly active users. Include poems, novellas and serial chapters, and its virtual shelves buckle under 565 million texts.

Now the Canadian startup wants to turn some of them into print.

Online book-reading spaces are proliferating. They include Tor (for science fiction and fantasy), Tapas (comics) and Radish (serialized novels). Wattpad has cornered romance — with an estimated $1 billion in annual book sales in America alone not counting self-published ones.

Along the way, said Porter Anderson, editor of Publishing Perspectives, an online trade journal, it has also tried to solve an age-old problem in the publishing business: how to foretell hits.

Books are costly to promote and, in print, to distribute. For every bestseller, they still plug plenty of duds. This is especially true for debut novels by unknown authors.

Wattpad's algorithm skims its uploads, as well as user comments and other data, to work out what appeals to readers. The site lets authors and fans interact — and writers to fine-tune their work to please the audience. High-scoring page-turners get promoted to advertisers and publishers. "After," a book which was viewed 1.5 billion times on the site, was snapped up by Simon & Schuster and made the New York Times bestseller list.

In 2018, Netflix released "The Kissing Booth," based on a Wattpad book by an American author who wrote it when she was 15. It is planning a sequel.

Wattpad, which makes most texts available free of charge, takes a cut of any book or film deal struck, as a literary agent does. It wants to emulate traditional publishers, too. It is toying with paywalls, and in January said it will churn out print runs of its algorithm's top picks.

Last year, Wattpad raised $51 million from venture capitalists, reportedly valuing the company at $400 million. However, Wattpad will not say if it is making money.