And you can't explain the difference entirely in terms of output. Similarly, you can't blame the size of the romance market on a shadow nation of professionally unfulfilled housewives located exactly 53 miles west of Peoria. The Environmental Protection Agency placed the American housewife on the endangered species list in 1984, and the long-term survival forecast looks grim. No, the people who buy romances are the same people who buy mysteries, suspense, science fiction, fantasy, westerns and mainstream fiction. It isn't just the thrill of a good love story.
Most fiction incorporates some form of romance.
Romantic complications drive too many conflicts to fail to make their mark on all forms of writing. It sells because it offers more of what people want in all their fiction. And I don't mean happy endings. Open any book on writing romance, and the first thing you'll learn is a successful romance relies more on characters than on plot. If your readers don't identify with, yearn for and lust after your characters, your story is dead before it hits the page.