From a New York Times article on e-books:

At Harlequin Enterprises, the Toronto-based publisher of bodice-ripping romances, Malle Vallik, director for digital content and interactivity, said she expected sales of digital versions of the company's books someday to match or potentially outstrip sales in print.

Harlequin, which publishes 120 books a month, makes all of its new titles available digitally, and has even started publishing digital-only short stories that it sells for $2.99 each, including an erotica collection called Spice Briefs.