For technology companies birthed during the heady bubble days and still in business now, the good news is they survived.

The bad news is they have to keep surviving … and pay back patient investors still seeking returns.

Of the 4,757 companies backed by venture capital firms in 1999 and 2000, only 128, or less than 3%, have gone public, while others have been acquired or gone out of business, says Robert Hoffer, managing director at Newforth Partners LLC, a technology-focused investment banking and consulting firm, who cited information published by Dow Jones VentureOne.

That leaves roughly 1,400 Web 2.0 companies looking for the door, with Hoffer predicting "400 disappearances through a variety of means, including mergers, acquisitions and deaths."

Increasingly, these companies are looking to joint ventures with other businesses to enhance their product offerings and expand their market share.

Technology and marketing partnerships among the surviving Web 2.0 companies is one result of the ongoing fight for survival, as a means of competing "considering the immense traffic at only a handful of sites," Hoffer says. And, while not always friction-free, partnerships such as one announced May 1 by social networking site Reunion.com Inc. and people search engine Wink Technologies Inc.'s Wink.com can help determine whether such exits are successful.

A self-described people search engine, Mountain View, Calif.-based Wink.com finds active Web and social network users by searching more than 175 million public profiles posted across social networks and online communities.

Founded in 2002, Reunion.com, of Los Angeles, bills itself as a means of adults reconnecting with old friends, relatives and classmates. The site acquired HighSchoolAlumni.com from IGN (then Snowball) in 2002 and PlanetAlumni.com with a combined membership of 6.7 million users. Reunion.com claims to add 40,000 new members every day to its 30 million person database.

The multiyear agreement means Reunion.com users will have access to Wink's people search capabilities, while Reunion.com will distribute Wink's services to other people search sites, the companies said in a statement.

Reunion, which offers the chance to "hook up with the guy you had a crush on in high school, can [now] leverage Wink's technology to find that guy," says Sharon Weinbar, managing director at Scale Venture Partners, formerly known as BA Venture Partners, the one-time venture capital arm of Bank of America Corp.

"If you're medium-sized in a crowded space, you're almost irrelevant," Weinbar says of social networking sites.

"This sort of cross-pollination is a much better model of the VC community than the idea that they merely support their own ventures — almost to the exclusion of the investments made by their colleagues," says Hoffer, adding that the VC community could be viewed as a trading group of sorts, exchanging the services of their collective portfolio companies.

Recent history offers ample evidence of the pitfalls of failing to link services with others, Weinbar and Hoffer say. Four-year-old photo-sharing Web company Photobucket Inc., for instance, managed to overtake more established rivals after positioning itself as a tool for folks using popular social networking sites including MySpace.com and Facebook.com.

MySpace in April resolved a dispute over advertising and lifted a temporary ban it had imposed of photos stored on Photobucket. (MySpace parent News Corp. is reportedly in talks to buy Photobucket.)

Conversely, FilmLoop Inc. is now being discounted as among the dead or soon to be departed. The Web site, which lets users make photo slide shows for viewing on desktop applications or Web sites, initially failed to give users the ability to embed slide shows into MySpace and other social networks, helping lead to its decline.

And, while heralding the value of partnerships between Web 2.0 companies, Hoffer also advises executives to keep their eyes on their firm's overall objective and be wary of building value around other people's business space.

"It is possible those don't disentangle well upon liquidity," he says of some joint initiatives.