NLINE dating once seemed the perfect option for Allison Gold, a stock trader in Manhattan. It was a vast, exhilarating marketplace, humming along with the efficiency and unlimited opportunity of the financial markets of Wall Street, where she makes her living.

Ms. Gold — lithe, outgoing, athletic, blond — seemed to have plenty to sell. And judging by the profiles of men on Match.com, the buy side had no shortages either. If she wanted a guy with green eyes — and she sort of did — she could type that requirement right into the search field alongside the desired height, income and ZIP code.

"At first, you're like a kid in a candy store," said Ms. Gold, who is 46. Hundreds of men answered her ad, and they all seemed great. "They're perfect," she said, referring to the way men portrayed themselves in their profiles. "They're all like the guys from `Ocean's Eleven.' "

Then she got a closer look. On dates, more than a few of the handsome, rugged, athletic types she thought she had been corresponding with looked more like George Costanza than George Clooney. Some of those "single" guys turned out to have wives.

Feeling weary and, she said, "jerked around," Ms. Gold let her paid subscription to Match.com expire, and she has turned to real-life singles mixers for professionals. "I think I just burned out," she said. "It's kind of like communism. On paper, it's a perfect system."

Apparently, many others have also found that the god of online dating has failed.

"It's clear that it's plateauing," said Peter M. Zollman, the founder of Classified Intelligence, a consulting company that focuses on online advertising. "A lot of people feel like, `I've been there, done that. I've met everybody there is to meet. I'll take a break.' "

Evidence is appearing that after years of rocketing growth, the online dating industry is drifting to earth. In 2002 the industry's revenues rose 73 percent over the previous year's, according to industry reports, and in 2003 they grew again by 77 percent. This year the growth has cooled, relatively speaking, to 19 percent, and tepid increases are forecast for coming years.

"The slowing has begun," said Nate Elliott, an analyst at Jupiter Research in New York.

Many early adopters — those quick to explore innovations — are moving on to the next big thing, which looks a lot like the last things on the dating front: bars, real-life matchmaking services, setups arranged by friends.

Consumer spending on online personals dipped during the first two quarters of this year, to less than $114 million a quarter from about $117 million in the final quarter of 2003, as measured by comScore Networks, a research company in Reston, Va. "Virtually any new industry goes through a period of rapid growth and expansion, followed by some adjustment," explained Daniel E. Hess, a vice president of the firm.

This industry, apparently, is adjusting busily. In September Match.com laid off 10 percent of its work force and replaced its chief executive. Its third-quarter sales inched up 3 percent over the same period the previous year, and profits dropped 37 percent, a decrease that one executive at the company attributed to a rise in marketing costs.

An online service called True, which started up in Irving, Tex., in January, has already slashed 60 percent of its 162 original employees, though it says it is now rehiring. Spring Street Networks, which operates the dating networks for Nerve and The Village Voice, has recently made significant staff cuts. In August MatchNet, a company in Beverly Hills that operates JDate.com and AmericanSingles.com, backed off from plans to go public.

All of this is not to say that Internet dating as a business is on the ropes. Niche sites — catering to elderly singles, lesbian singles, obese singles — continue to spring up. More than 800 online dating sites now exist, according to Hitwise, a company that tracks Web industries.

But as a heady pop-cultural revolution — otherwise known as a fad — the Net no longer seems to have the capacity to reinvent the world's mating rituals. A moment has passed.

"There's a burnout factor that's almost inevitable in the online dating world," said Mr. Zollman of Classified Intelligence. In other words, either you find lasting love or you grow sick of surfing for it. At Match.com, which says it has 50 million profiles in its database, subscribers stay for only about five months on average, said Joe Cohen, the chief operating officer. (Subscriptions start at $24.95 a month.) He emphasized that about 40 percent of those who leave eventually return.

"We've tried a number of things to keep them around longer," he said. "But you know what? We don't really want them to stick around longer. We want them to find partners."

The clearest measure of a nascent weariness with online dating may be the expansion of defiantly offline dating services, some of them set up to cater to frustrated refugees from the Web.

"People think online dating has hurt our business when in fact it's made it grow," said Sherri Murphy, who operates a matchmaking service called Elite Connections in the Los Angeles area. She charges singles $795 to $5,000 to help them find mates among clients she says are carefully screened. "Online dating is a job in itself," Ms. Murphy said. "People come to us to relieve the burden."

As Renée Piane sees it, "Online, there's no connectedness." Ms. Piane is the president of Rapid Dating in Santa Monica, Calif., one of several companies around the country that now manage "speed dating" parties where singles cycle through a rapid-fire series of five-minute minidates (a bit like musical chairs for grown-ups), so they can get a sense of whom they might want to date. "You can't tell if there's any chemistry" online, Ms. Piane said. "With speed dating, you know in the first five minutes."

Ms. Piane canceled her own subscription to Match.com in May 2002, around the time she ran across, in person, an old high school acquaintance she soon fell in love with. She complained that her profile is still available on Match.com, giving false hope to hundreds of men, and said she has deleted more than 200 e-mail messages from eager bachelors in the last few weeks alone.

Perhaps no one has been quite so literal in trying to build a business around online burnout as Ilana Eberson. Ms. Eberson, who worked at Jcupid.com, a former online dating site for Jewish singles, started a company called Real Live People Party four months ago.

"The whole concept is, `Disconnect from the Internet, reconnect with real life,' because we all agree that the bloom is off the rose with online dating," Ms. Eberson said.

It's not that Ms. Eberson's offline alternatives are revolutionary. So far, her company has held several singles mixers at New York bars, and she is planning to put on a scavenger hunt at the Metropolitan Museum of Art as well as a singles cruise. But she maintains that her timing is just right. After a few euphoric years mouse in hand, people are jaded about online dating, she said.

On her company's Web site, http://www.reallivepeopleparty.com/ (yes, even offline dating services have Web sites), she started a contest in which the best tale of an "online date from hell" will earn free entry to a party.

Dr. Marty Klein, a marriage and family counselor and sex therapist in Palo Alto, Calif., said: "What always happens with new technologies, whether it's computers or cellphones, is that at first there are early adopters. Then it gets out into the commercial realm. Your grandma gets one. It's always over-hyped in the beginning, then turns out not to be the answer to everything, so some people with unrealistic expectations blame the technology. Like everything else, there's a predictable cultural curve to it."

Jill M. Horn, a real estate manager who lives in Manhattan, said that after divorcing in 2001 she joined about five paid dating sites. E-mail begat more e-mail. There were personality tests and phone calls.

"It's a lot of effort, and it's really no different from the people you meet in the offline world," she said. "I'm becoming disenchanted. I've got people contacting me from North Carolina and New Mexico, and that's not going to work."

"The argument is that technology is supposed to make your life easier, but that's not necessarily the case," she added.

Rosie Koul is an information technology specialist for the automobile industry who lives in a suburb of Detroit. Now 34, she divorced three years ago and immediately turned to online options like Kiss.com, as many of her single friends had done.

An expert in marketing data, Ms. Koul kept meticulous records of her online activities. Last year, in one nine-week period, her profile was browsed 4,212 times, mostly during the first four weeks after it was posted. At one point, she said she did fall in love with a man online, or at least his profile. In print, he was clever and engaging. She laughed out loud as his witty e-mail. Finally, they agreed to speak on the phone.

Nothing.

"I don't know what happened in the exchange, but he was boring," she said glumly. "I even went back to the e-mails to make sure I was talking to the right guy."

"Having been a marketer, there's a point of diminishing returns," Ms. Koul added. "Do I want to spend all these hours at my PC or out having fun and meeting people?"

Lately, she has turned to a service based in nearby Royal Oak, Mich., called Table for Eight, which organizes intimate dinners of four women and four men, about 70 percent of whom have had their flings with online services, said Regina Stocco, the company's president.

While most women interviewed complained that too many men just "window shop" online and are unwilling to consider any but the prettiest faces, Zev Guttman, 28, a mortgage banker in Monsey, N.Y., said it was men who are at a disadvantage online: it is still typically the man who has to make the first move, and it is still the woman who gets to pick and choose.

As a result, he said, he either had to lie — about, say, the fact that he is divorced — or face an empty mailbox every day. "If I write that I'm divorced, I don't have a chance of hooking up," he said. "If I write that I'm single, they're not interested because they think I lied to them" once they discover the truth.

"I'm just going to go back to matchmaking, or friends," he said.

For every Zev Guttman who lets his screen go dark, another lovelorn hopeful will undoubtedly rise in his place. Bill Tancer, a researcher at the Redwood City, Calif., office of Hitwise, said a lot of the industry's growth will come from groups arriving late to the online singles scene, like the elderly.

And technology being technology, online dating continues to morph. Stuck in line at the post office? You can now pass the time hunting for a life partner, or at least a quick hookup, on your cellphone, using Match.com's mobile service. The True online service screens for both felons and cads through a partnership with Rapsheets, which reviews public records to verify that people claiming to be single in their profiles actually are. Yahoo Personals offers the opportunity to include a 30-second video clip in profiles as an opening line.

Hey, it's almost like meeting someone.

In a sense, the fate of online dating is probably a bit like that of singles bars. There are still singles, and there are still singles in bars. But the "singles bar" that caused such a frisson became a relic of the "Looking for Mr. Goodbar" 1970's. It became ordinary.

That is probably one reason that online dating seems to have lost its buzz among its own Generation 1.0. "In the last five years, it's become so mainstream," said Sherrie Schneider, an author of "The Rules for Online Dating" (Pocket Books, 2002), who remains a great champion of the practice. "It's your boss. It's your co-worker. Every single woman in my neighborhood is on Match.com. It's like brushing your teeth."