Harlequin Books, which releases more than 120 titles a month, is putting its catalog online as e-books. That will make erotic pulp even more accessible. The romance genre controls more than half of the paperback fiction market, according to the Romance Writers of America. It's the fastest-growing area of women's fiction. No wonder, with titles like Cold Case, Hot Bodies from the Harlequin "Blaze" series — now available online for $3.99.