How did love stories about vampires, cowboys, and wealthy dukes become the highest-grossing fiction genre in the world? Zachary Crockett gets swept away.  SOURCES:Delaney Diamond, romance novelist.Danielle Flores, high school math teacher and avid romance novel reader.Brenda Hiatt, romance novelist.Diane Moggy, vice president of editorial at Harlequin.RESOURCES:"Even as Overall Book Sales Are Declining, Romance Novels Are on the Rise," by Elena Burnett, Sarah Handel, and Juana Summers (All Things Considered, 2023)."Key Takeaways from the Authors Guild’s 2023 Author Income Survey," press release by the Authors Guild (2023)."How Amazon Turned Everyone Into a Romance Writer (and Created an Antitrust Headache)," by Ann Kjellberg (Observer, 2022)."Vivian Stephens Helped Turn Romance Writing Into a Billion-Dollar Industry. Then She Got Pushed Out," by Mimi Swartz (Texas Monthly, 2020)."A Brief History of the Romance Novel," by Amanda Pagan (New York Public Library Blog, 2019)."How Harlequin Became the Most Famous Name in Romance," by Kelly Faircloth (Jezebel, 2015)."Fifty Shades of Amish: A Strange Genre of the Romance Novel," by Leah McGrath Goodman (Newsweek, 2015).