The online dating industry is a $2.1 billion business, with niche dating sites claiming more and more of that market share.
We talked to the men and women behind niche dating websites to find out what makes their crazy ideas so successful.
From simple revenue models to familiarity with their customers, niche dating site creators believe they have a handle on their specific market.
We also asked online daters what drove them to join the super-tailored sites and whether they have found love in the digital world.
Noel Biderman, CEO
Ashley Madison, the website for people looking to have affairs, has the honor of being the largest niche dating site in the world, Biderman said.
He got the idea for the site in 2001 after reading a news story that claimed about 30 percent of people on dating websites weren’t actually single.
Since 2001, the site has grown to 13.2 million members worldwide, nearly 8 million of whom live in the United States. The adultery website raked in more than $50 million in 2011 and predicts profits upwards of $80 million in 2012.
Registration for the site is free and members purchase Ashley Madison credits that can then be used to contact other members. Members can also purchase virtual gifts like virtual champagne or virtual roses.
The site might be thriving, but it isn’t without its enemies. In 2008 the Archdiocese of Massachusetts decried the site’s ads.
But, his site is serving a purpose, Biderman said. It gives married people a way to get off sites like Match and, in some cases, it can help users strengthen their primary relationship.
Biderman said he heard from one user who was caring for his wife with Alzheimer’s, and when the disease progressed, the man said he felt uncomfortable being intimate with his wife because she didn’t recognize him.
The man joined Ashley Madison and found a lover whom he saw once a week. That arrangement 
allowed the man to preserve his life and continue caring for his wife, Biderman said.
Steve Urow, CEO and Creator
He created VeggieDate as a safe place for vegetarians to share their lifestyle with other vegetarians around the country. Plus, at the time he created VeggieDate, there weren’t many vegetarian sites and people needed a way to connect, he said, adding, “it’s important to be on the same wavelength.”
VeggieDate, which launched in 1999 and has around 13,000 members, makes money through a combination of membership fees and ads. Urow offers members a free two-week trial, after which memberships cost $10 for three months or $20 for a year.
“I make strong efforts to be vegan and I say I’m nearly vegan,” he said of his connection to the site.
Meet VeggieDate user Randy K., who created a VeggieDate profile on a whim and wound up a wife.
Randy K. met her husband Glenn in 2007 after posting a profile to the site. But romance wasn’t her ultimate goal when she checked out the vegetable-friendly site.
After checking out veggie-only recipes, she said she searched for vegetarian dating sites just for fun. Randy, who was 50 years old when she met Glenn, ultimately found VeggieDate and spent a few minutes filling out a profile.
When she and Glenn connected on the site, they emailed for about a week and talked on the phone for about a month before finally meeting.
“The first thing I said to him was ‘Can I see your driver’s license?” Randy said about their initial meeting.