After five years, she left.

Now in his early 30s, Jacob felt he had no idea how to make a relationship work. Was compatibility something that could be learned? Would permanence simply happen, or would he have to choose it? Around this time, he signed up for two online dating sites: Match.com, a paid site, because he’d seen the TV ads; and Plenty of Fish, a free site he’d heard about around town.

“It was fairly incredible,” Jacob remembers. “I’m an average-looking guy. All of a sudden I was going out with one or two very pretty, ambitious women a week. At first I just thought it was some kind of weird lucky streak.”

After six weeks, Jacob met a 22-year-old named Rachel, whose youth and good looks he says reinvigorated him. His friends were jealous. Was this The One? They dated for a few months, and then she moved in. (Both names have been changed for anonymity.)

Rachel didn’t mind Jacob’s sports addiction, and enjoyed going to concerts with him. But there were other issues. She was from a blue-collar military background; he came from doctors. She placed a high value on things he didn’t think much about: a solid credit score, a 40-hour workweek. Jacob also felt pressure from his parents, who were getting anxious to see him paired off for good. Although a younger girlfriend bought him some time, biologically speaking, it also alienated him from his friends, who could understand the physical attraction but couldn’t really relate to Rachel.

In the past, Jacob had always been the kind of guy who didn’t break up well. His relationships tended to drag on. His desire to be with someone, to not have to go looking again, had always trumped whatever doubts he’d had about the person he was with. But something was different this time. “I feel like I underwent a fairly radical change thanks to online dating,” Jacob says. “I went from being someone who thought of finding someone as this monumental challenge, to being much more relaxed and confident about it. Rachel was young and beautiful, and I’d found her after signing up on a couple dating sites and dating just a few people.” Having met Rachel so easily online, he felt confident that, if he became single again, he could always meet someone else.

After two years, when Rachel informed Jacob that she was moving out, he logged on to Match.com the same day. His old profile was still up. Messages had even come in from people who couldn’t tell he was no longer active. The site had improved in the two years he’d been away. It was sleeker, faster, more efficient. And the population of online daters in Portland seemed to have tripled. He’d never imagined that so many single people were out there.

“I’m about 95 percent certain,” he says, “that if I’d met Rachel offline, and if I’d never done online dating, I would’ve married her. At that point in my life, I would’ve overlooked everything else and done whatever it took to make things work. Did online dating change my perception of permanence? No doubt. When I sensed the breakup coming, I was okay with it. It didn’t seem like there was going to be much of a mourning period, where you stare at your wall thinking you’re destined to be alone and all that. I was eager to see what else was out there.”