SAN FRANCISCO: Virtual beer and vampires may no longer be enough to keep members of social networks like Facebook and News Corp.’s MySpace riveted to their computers.

Instead, the key to the future of these Web sites may lie in more practical functions, like making plans, booking tickets or checking stock quotes.

“Right now, the big challenge for social networking services is finding a way to simultaneously encourage user loyalty and revenue growth,” said Ri Pierce-Grove, an analyst with Datamonitor, a research firm.

Simply put, if people do more things on social networks, they stay online longer, share with friends and reveal more about their tastes and habits, allowing advertisers to focus their messages better. Advertisers usually pay sites based on the number of times an ad is clicked, and people are more likely to do that if the ad is specifically aimed at them.

EMarketer, a research firm, predicts that U.S. advertising spending on social networks will exceed $1.6 billion this year as the sites and companies that make applications for them push to harvest more personal information posted online, then sell it to advertisers.

But the search for the best way to do so is still on.

Advertising on Google’s social networks, including a partnership with MySpace, brought lower-than-expected revenue in the fourth quarter, Sergey Brin, a co-founder of Google, said in January.

“I don’t think we have the killer best way to advertise and monetize social networks yet,” he added.

Meanwhile, people may be tiring of the activities that social networks do offer.

Although these sites have added thousands of members in the past year, comScore data show that fewer people are signing on, and members are visiting their profiles less.

For instance, the number of U.S. visitors on MySpace fell to 68 million in February from about 72 million in October, while the average time people spent on their Facebook profiles dropped to 161.3 minutes from 195.6 minutes.

This indicates U.S. social networking is at the “mature stage of the growth curve,” said a comScore spokesman, Andrew Lipsman.

Part of what made social networks popular are widgets. One of these small programs, “Vampires,” lets members virtually “bite” friends. Another application allows people to prod their friends virtually by sending messages that they have been “poked.”

Millions of people got hooked on these widgets, creating a new audience – and potentially a new market – for advertisers hoping to tag their messages to these applications.

The excitement around widgets touched a high point in January when Slide, which makes a tool that lets people create slide shows and put them up on any social network, secured $50 million from large institutional investors.

But some wonder whether squeezing sustainable cash from this audience will require more than fun and games.

Investors “are going to lose of lot of money,” said Charles Moldow, general partner of the venture capital firm Foundation Capital. The widgets currently in fashion are very “lightweight” and do not command the loyalty of their audiences, he said.

Social networks benefit from engaged users who share their likes and dislikes with friends, helping advertisers through word-of-mouth, or “viral marketing.”

“If you can tap into that and then there’s sharing, if you have a big audience that’s engaged with you, you will be able to make money off it,” said David Card, an analyst with Jupiter Research.

Although many fun-and-games widgets do have this viral power, analysts believe there is more money to be made by making these applications richer.

Useful widgets that let people share experiences aid viral marketing and increase the efficacy of targeted advertisements, while keeping people online longer.

“Widgets that keep you updated on concert tour dates for your favorite bands, weather widgets – there’s a lot of promise in that kind of campaign,” Card said.

A conviction that this is the road to success for social networking has led many investors to fund useful widgets.

Silicon Valley venture firm Khosla Ventures and IAC/InterActiveCorp’s Ticketmaster have invested in iLike, a program that lets people post songs on profiles and has a link to Apple’s iTunes store so friends can sample and buy the music.

But many analysts cautioned that marketing tailored to people’s online behavior – while an exciting opportunity for companies – might not succeed if people feel their privacy is intruded upon.

Sites are also grappling with the challenge of serving up unobtrusive ads that will entice users to click and share with friends.

SAN FRANCISCO: Yahoo said it would join an alliance to be led by Google, its principal rival, that will try to make it easier for programmers to write software that can run on the pages of many social networks and other Web sites.

Google announced Tuesday that it would give up control of the alliance and turn it over to a nonprofit foundation. Google, Yahoo and MySpace, another member of the group, will be among founding members of the group, the OpenSocial Foundation.

The addition of Yahoo broadens the potential reach of the foundation. The group is working on standards that will let developers create programs that can run on any social network or Web site that embraces them. Such programs might, for example, allow users to let friends know the music or movies they enjoy.

The creation of the OpenSocial alliance last fall was widely seen as a response by Google and others to the growing power of Facebook, which has persuaded thousands of outside developers to build applications for its site. Those applications have helped bolster Facebook’s popularity.

The creators of many of the most popular Facebook applications have since said they plan to adapt their programs to be compatible with OpenSocial.

Although Google is not a major force in social networking, its rivalry with Facebook appears to be intensifying. Facebook, for instance, has signed an advertising partnership with Microsoft and has recruited several prominent programmers and executives from Google, including Sheryl Sandberg, who became Facebook’s chief operating officer.

A Facebook spokeswoman, Brandee Barker, said it would not be part of OpenSocial. “Facebook is not joining this foundation, but the company remains focused on advancing Facebook Platform to benefit the developer community and help users communicate and share information more efficiently,” Barker said.

Yahoo considered joining the alliance for months, according to a person with direct knowledge of its plans. But Yahoo executives worried that Google might exert too much control over the evolution of the alliance and over intellectual property it created, that person said.

In a conference call with reporters, Google and Yahoo executives dismissed the idea that the decision to put OpenSocial in the hands of a foundation had been a response to Yahoo’s concerns.

Joe Kraus, director of product management at Google, said the foundation represented “more an evolution of where OpenSocial is heading” than a response to concerns raised by any one member. And Wade Chambers, vice president for platforms at Yahoo, praised Google’s stewardship of the standard so far.

The foundation, to be created within 90 days, will “ensure the neutrality and longevity of OpenSocial as an open, community-governed specification for building social applications across the Web,” the companies said.

Yahoo gave no details on when or how it would adopt the OpenSocial standards. So far, only MySpace and Orkut, Google’s social network, have introduced OpenSocial, Kraus said.