Since its launch, e-content aggregator Books24x7 has built a lucrative e-publishing business by offering professionals easy online access to thousands of technical and reference texts while collecting valuable marketing and consumer-use data for its publishers. And the royalties Books24x7 pays to its publishers is growing right along with the size and depth of its online libraries.

Since the first of the year, Books24x7 has added more than 100 books across all of its collections, for a total of 13,139 books, or nearly 4.6 million pages. Under its model, Books24x7 offers publishers of business and technology titles an efficient way to monetize their digital content. "It's one of the best models for publishers, and actually pays us and our authors money for using our content," said Patricia O'Hare, president of Nicholas Brealey Publishing North America.

Books24x7 charges an annual subscription fee (based on the number of users at each business-subscriber) to the companies that subscribe to its libraries. The company pays its publishers quarterly from a royalty pool and the most accessed titles can earn as much as $20,000 a quarter.

Subscribers—generally business and IT professionals—also buy physical books through the site, in addition to leaving a trail of invaluable consumer data. "Because the content is consumed online and hosted on our computers," said Books24x7 director of public relations and product marketing Pam Boiros, "we capture all the footsteps. At the end of each quarter, we do a massive roll-up." At the same time, Books24x7 gathers data on how many users click through and purchase books. Boiros said that the company generates approximately $25,000 a quarter in book sales through Amazon (publishers can link to the online reseller of their choice). Boiros also pointed up another advantage of Books24x7: it lets editors know how their books are used by providing data on which chapters are viewed and how frequently.

Books24x7 does its own digital conversion at no cost to publishers. The company offers subscribers a rich online reading experience with a search function, digital bookmarks and shared pages. The company recently launched On the Go, a Web site that enables subscribers to access their accounts using PDAs.

Kris Kliemann, Wiley v-p and director of global rights, said e-content aggregators like Books24x7 are generating a large portion of Wiley's digital rights revenue stream. "Digital rights is now about 25% of our total," he said. "Ten years ago, it was 10% or less." Similarly, McGraw-Hill spokesperson Tom Stanton also attributed a significant percentage of the licensing revenue at McGraw-Hill Professional to the growing demand for digital content from computing, engineering and medical/scientific professionals. "By every measure," Stanton said, "it has been a very successful alliance" with Books24x7.