"If people can share an interest with someone off the bat," says Sandler, who plans to have her site up and running by November, "then they are that far ahead in finding someone that they are compatible with."

Mainstream sites contend that bigger is still better.

"When it comes to this particular industry, size definitely matters," says Kristin Kelly, senior director of public relations for Match.com, who says the site signs up 60,000 new members daily. "The main reason you go online is to expand your possibilities, so having a really large range of people is important. From there, you can be as broad or as narrow as you want to be. You define the pool."

With more than 800 online dating Web sites out there, competition is fierce for these niche sites. Still, one out of every 100 Internet users is logging on to dating Web sites, according to Bill Tancer, general manager of research at Hitwise, an Internet market research firm, which means there always seem to be people who are looking for something -- or someone -- more specific.

"The trend has been that the new sites have to differentiate themselves somehow from the others," Tancer says. "They have to offer new features and appeal to a very, very specific subcategory of the dating industry."