The race is on to see which fashion social networking sites can attract the most members, traffic and advertisers. It remains to be seen whether social networking sites devoted to a particular topic, which are proliferating on subjects as diverse as genealogy and fitness, can grow as large as general ones such as MySpace and Facebook.

Social networking sites allow members to create their own profiles and link to those of others. At the general sites, which also include Friendster and LinkedIn, the main activity is connecting to friends. At topic-specific sites, the main activity might be something else, such as sharing photos of outfits, music playlists or information about family trees.

Fashion-specific social networking sites include MyStyleDiary, Iqons, ShareYourLook and StyleMob. Shoutfit has closed down, and MySpace recently created a fashion-specific page within its larger site. Other types of fashion sites, such as ad network Glam and blog network Sugar Inc., include social networking areas where members can create profiles.

If fashion social networking sites take off, they could become an important advertising medium for fashion companies that want to reach a particular type of fashion consumer. So far, retailers and designers have been eager to experiment with the medium and have created their own profiles, sponsored contests, posted videos and purchased banner ads on sites such as MySpace and StyleMob.

Social networking sites of all types are growing in popularity, with 16 percent of adults who are online using them, according to Forrester Research Inc. Marketers predict social media (a broad category that includes blogs) will increase in effectiveness in the next three years. In 2007, marketers spent $600 million on social media, and that figure is expected to more than double to $1.5 billion next year and to rise to $6.9 billion by 2012.

MySpace launched its fashion page in August and has about 70,000 friends, or profiles, in the community. “It’s for people who have any sort of interest in fashion, from small to large,” said MySpace director of marketing Todd Dufour. The page focuses on emerging fashion and highlights the pages of selected stylish members and designers each week, such as Brooklyn, N.Y., men’s wear designer Yoko Devereux. In Style magazine contributes a fashion news feed, and MySpace produces original video for the page in “My Fit,” which has profiled Nicky Hilton and Charlotte Ronson. Small designers can set up a profile at no charge, whereas bigger companies, such as Bongo, pay a fee.

This story first appeared in the November 14, 2007 issue of WWD. Subscribe Today.

StyleMob also launched in August and has 13,500 members. About 30,000 people visit the site each month, most returning members. Although the site has no marketing budget, it is adding 2,500 members a month by word of mouth. The site is focused on street fashion, and members can share and rate looks or assemble a team of stylist advisers. It has daily contests (themes have included “wow,” Halloween and “clothes you covet”) and prizes have included Zune music players, Mavi jeans and handcrafted jewelry from Etsy sellers. GenArt and Microsoft are both sponsoring a contest this month, but StyleMob does not yet accept advertising, preferring to focus on growth.

Iqons, a London-based site with deep connections in the French and U.K. fashion industry, launched in October 2005 and now has 15,000 members, many of whom work in fashion.

“So far, we are attracting interesting people from a creative point of view,” said Iqons co-founder Rafael Jimenez. “We are studying how to make them famous, how do we create an audience for them? And how do we interest the typical consumer without disappointing the creative people?”

The site has decided to remain a club of insiders and grow slowly rather than aim for the mass market like MySpace. John Galliano is a featured guest this month, Katharine Hamnett was on the site for July and August, and Jean-Charles de Castelbajac will appear in February. Vivienne Westwood and Alber Elbaz did not appear earlier this year as promised, but will be guests soon, said Jimenez. Guests post a profile, talk to members online, view portfolios and offer advice.

Nike has sponsored one of the site’s design contests, and cosmetics companies plan to sponsor the site during New York Fashion Week, Jimenez said. Former Saatchi & Saatchi chairman Lee Daley is an adviser to Iqons. The site is mulling complementary ventures into e-commerce and publishing.