The people on the other side of the velvet rope have moved onto the Internet, and now they are trying to exclude you from their Web sites, too.

The sites that originally defined what has come to be known as "social networking," like the now-famous Friendster and online communities such as MySpace.com, let anyone join. Their aim was to let members benefit from the theory that everyone is connected by no more than six degrees -- that your friend's cubicle mate knows someone whose sister's college boyfriend should definitely be dating you and who it turns out went to junior high with you. Then, they try to help people use those connections by mapping them out on a Web site and giving members a way to get in touch with others. Some people use the sites for finding a job or an apartment or to track down a former classmate. Others use them as a networking tool.

Now, in a bid to build a new networking model beyond Friendster (www.friendster.com), an increasing number of sites are touting their exclusivity. A site called aSmallWorld (www.asmallworld.net) is geared toward those who regularly jet among places like St. Barths, London and New York. In November, it stopped letting the majority of the members invite others to join. Now, only 1% of the 60,000 members can do so, including people in countries like Brazil where the site wants more members.

On Catch27 (www.catch27.com), which claims thousands of users and touts itself as the "most hip," member profiles appear as baseball cards. The site encourages members, many of whom fall between the ages of 18 and 30, to trade their friends for "hotter, smarter ones," and rank others by their "looks" and "smarts." The site also is launching a "black ball" feature that some members will be able to use to kick others off.

Elsewhere, FunHi (www.funhi.com), with more than 150,000 active users, seeks to emulate a club and "bounces" users who lack style, like "meatheads" and people who "look homeless," according to Ray Savant, the site's co-founder. He estimates the site has bounced 20% of aspiring members. The site changes its invitation policy every few weeks.

The debate over how exclusive to be mirrors a broader issue facing many Internet businesses: whether to attempt to attract millions of eyeballs -- or to focus on a smaller but more devoted group of users. While people in the latter category might spend more time on the site or even be willing to pay a fee to use it, the former strategy can yield the kind of mass that some advertisers are seeking.

The sites' founders think the Friendsters of the world went wrong by letting anyone in -- and that, as a result, those pioneering services lost the feeling of a community mirroring an actual clique. They figure if they screen members, those that pass muster will better trust the travel tips, job leads, or date fix-ups from others.

Then, there is the question of how to profit from the sites. Friendster, which takes in revenue through advertising, says it just became profitable this year. While its rivals with their restrictive door policies aren't likely to generate massive earnings as a result of their smaller size, some of them already claim to be profitable. For example, FunHi, a unit of New York's Revenant Global LLC, says it is showing a profit by encouraging users to pay at least $9.99 for full membership and to pay more to keep sending other users virtual gifts.

ASmallWorld plans a premium membership service where members would pay for additional features. It hopes to have at least 50,000 paying members within a year and to be profitable by the fourth quarter.

The Internet was conceived as an open place for sharing academic research. As it grew, exclusivity emerged in the form of private bulletin boards or listservs. In 1996, for instance, New York's Echo virtual salon let any user create private conference areas.

The new focus on exclusivity comes as many social networking sites have been struggling to keep users interested once the novelty of seeing personal connections mapped out wears off. Less than half of Friendster's 16 million registered users are visiting the site regularly.

In fact, many of the older sites have seen their buzz eclipsed more recently by business-networking sites such as LinkedIn (www.linkedin.com) and Ryze (www.ryze.com). These encourage people to invite their business contacts to join and then facilitate introductions between them. Anyone can join these sites.

Last year, Google Inc. launched orkut (www.orkut.com), one of the first invitation-only networking sites, but the company says it limited membership partly to expand in a controlled way rather than for the purpose of being exclusive.

The new exclusive sites are betting that sticking with a niche strategy will help boost user interest and willingness to pay. Denise Kaufmann Razzouk, a handbag designer who splits her time between New York, Paris and London and who says she is in her "late 20s," avoided joining a social networking site until she was admitted to aSmallWorld last June. Now, she visits it daily. "I wouldn't join another network because I'm not interested. It's not the same caliber," she says. "It's like all the people here will have the black American Express, but it's not nouveau riche."

Of course, most clubs cool off considerably a few months after opening. In fact, some new sites already are resorting to strategies like begging people to sign up via online ads. When a site called Closed Society (www.closedsociety.net) launched, it opened its first 100 registrations to the public via a Google ad: "Join now and be a VIP." Only about 40 people applied.

Beyond networking, the new sites offer practical features from travel guides to casting services for aspiring actors and models. On aSmallWorld, members must join the site using real names so users can get trusted recommendations for say, five-star restaurants. "You're not on a site that has millions of people, and you have no idea if someone says this is a great restaurant and you go there and then you end up eating at Denny's," says Renny Harlin, a film director in Los Angeles and an investor in the site.

"If we let it grow, we would have lost control of who is a member, and we thought that quality is much more important than quantity," says Erik Wachtmeister, who started aSmallWorld in March 2004.

The site's features include a 60-city guide; a directory for limousine services, jewelers and yacht brokers; and a forum where users can post messages like "Day spa London/Paris. Girls, I am in need."