Two years ago, Nancy Kaup was a 31-year-old single mother who was frustrated with dating. She had spent six months on the website eHarmony, filled out a 400-question survey about herself, and begun receiving daily "matches"—profiles of men whom the site deemed compatible. But none of them worked out. She decided not to renew her subscription. Two days before her profile expired, however, a man named Jon Anthony signed up for the service.

Nancy showed up in Jon's first round of suggested matches, and he contacted her. "He was my last match and I was his first," she says. Their first date was at a wine tasting in Albuquerque, New Mexico, where they both live. Although it lasted only an hour or two, the next day Nancy told her friends at work that she had met her future husband. "I knew right away," she says. "It's weird, because I'm not usually like that."