"There's several different ways compatibility is sought," Conru said. "People select characteristics that are most important to them and do a search, such as gender, sexual orientation, age, geographic location and height, and they get whole lists. And then we give predictions on how compatible you might be, based on whether or not you're passive or aggressive, for example. The various things we find are important when it comes to making good matches."
The basic formula for computer dating is derived from industry heavyweight Gary Kremen, president of Grant Media LLC, which owns Galaxy search.com and Sex.com. Kremen first became involved in the Internet in 1985 before it became publicly accessible and was limited to academic and U.S. Defense Department circles.
Kremen's first e-commerce venture was selling security software in 1991, when email existed, but not the web. Then Kremen went on to pioneer computer dating in 1993 with Match.com.
"I said, 'I bet I could get women in a database with pictures and sell memberships to men,'" Kremen said. "I wrote a business plan and software that used email only. I raised $2 million at first and over the life of it, more than $15 million from venture capitalists. The idea was to build an online dating company. It was based upon the idea that for every one woman, you could get into a database with a picture you could get 20 guys to pay to have access to it."
At the time of its inception, Match.com had no bells and whistles, and according to Kremen, there was no need for video. The company was eventually sold to Citysearch Ticketmaster.
"Few people have AVI clips of themselves," Kremen said. "The same goes for voice. Now pictures are different. Men want to see pictures. We started out with a list of 120 questions. We found that at the end of the day, none of them really mattered, other than about seven questions, which included the person's zip code — so you could determine distance — the sex of the person, and whether they were looking for a longterm relationship, short-term relationship or just a friend. Height, weight, religion, age and education also mattered."
Precision computerized compatibility that matches criteria is not essential, maintains Kremen, unless the service has a large enough database. Then, users can narrow their searches down to a partner who, for instance, likes Jacuzzis.
"In a sense, we like to believe we invented the affiliate program," Kremen said. "We had revenue-sharing deals with Women.com, Microsoft and others. The webmasters would make money the way people make money today through a split of recurring revenue."
Money is also made by selling banners to complementary companies, such as escort services and porn sites.
Kremen noted that the main difference between mainstream and adult personal ad sites is that questions on the adult side are more explicit. Preference criteria members are asked on Adult-DateLink.com's questionnaire whether they are looking for couples (for threesomes), transsexuals, transvestites and transgender, exhibitionism and voyeurism, sadism and masochism, fetishes or discreet relationships.
According to Conru, Adult-FriendFinder offers two affiliate programs that pay a dollar per click and larger affiliates make more than 80 percent of their revenue from renewals.
"A small percentage of our revenue is through upsales for our online store and links to other adult sites," Conru said. "We have a higher percentage of our upsale revenue from things such as private chatrooms. Affiliates also get their cut."
Favorite adult dating affiliate programs cited by the webmaster community include Sexsearch.com, Lovedollars.com, Iwantu.com, Match.com, Lovercash. com, Datinggold.com, Personalbucks.com, Sexyads.net, Adultcash.com, Udate.com and Eroticy.com.
In just 11 months, SexSearch surpassed 2.5 million member sign-ups.
SexSearch.com operates an online adult personals and swingers dating service that caters to adults seeking sex from other likeminded individuals. The team at SexSearch attributes its rapid growth to a change in the way that people are dealing with sex and relationships online.
According to DateApp.com CEO John-Michael Cataldi, "Developing the technology and keeping up with the greatest applications to facilitate the matching process such as video chat, member voice mail, SMS, cell phone and speed-dating technologies are cost-intensive to develop and deploy."
DateApp empowers its webmaster partner network to quickly create and customize dating site(s) within about 15 minutes, and DateApp handles all of the operational functions such as site administration, profile approvals, hardware maintenance, continual site upgrades and application development.
"For the partnered website, the real advantage comes from the ability to create an additional revenue source and gain valuable consumer data from existing site traffic," Cataldi said.
But just as in the offline world, computer-initiated dating has its ups and downs.
"There are lots of privacy and safety reasons why users of online services should avoid giving away too much personal information, other than the bare necessities for starting a relationship," Conru said. "For example, it would be quite foolish to give your home address to someone you just met, whether it's online or off. We really recommend people use Adult-FriendFinder.com's free email service, which they can use anonymously, simply to schedule a public location for you to meet, like a bookstore."
Kremen warned that in the non-adult world, policing is really important.
"Check to make sure each picture is acceptable content," Kremen said. "Look for prostitution ads. Make it a safe, supportive environment for women. These things are different in the adult space."
Kremen says he doesn't run an adult dating site now because he feels that with the adult version, the liability is much greater for the webmaster.
Another thing to look for is cyber scammers so that webmasters and customers aren't searching for sex in all the wrong places.
Kremen alleges that some sites use phony photos and text to lure male members and when it comes time to finally making a rendezvous, the man receives an email saying: "I've met somebody else."
In some cases, dating sites entice surfers with free membership offers. But generally, after filling out lengthy online registration forms, newcomers enter the site only to discover that to contact prospective partners, one has to fill out a new application, containing credit card information.
But regardless of some of the pitfalls, personal ad sites have mushroomed for both mainstream and adult markets. In addition, BusinessWeek reports, virtual dating services may soon compete with wireless giants such as Verizon, Cingular and Sprint.
"Text-messaging dating services are proliferating," the reports states.
Nevertheless, personal ad sites help supply one of the most basic human demands. Online adult dating services help customers cast a wider net beyond their usual social circles to search for partners.
As MSNBC noted: "Love, it turns out, is one of the few things people people are willing to buy online."