"Some are looking for sex because they are in sexless marriages with people they love or don't want to leave for other reasons but cannot have sex with," said Schwartz.
"Others are stimulation junkies -- they just can't be satisfied with sex with only one person, even if they love that person. Some people want to 'shake up' their lives, there are people with a 'kink', something they enjoy about sex that their partner wouldn't do."
Greg, 45, has no doubt about the effect AshleyMadison.com has had on his personal life. "I think it's fair to say that without (it), I would probably be divorced by now," he said.
"As strange as it seems, Ashley Madison has provided a way for me to fill a void in my life without having to break up my family."
Others meanwhile argue that monogamy is simply impossible if you possess a high libido. "As a woman with a high libido, I've realized it's not only unrealistic but indeed unfair to rely solely on one person to satisfy my needs," says Stephanie, 28.
Predictably, adultery sites have little time for the argument that they are a corrupting influence. Jay Thompson, a spokesman for datingforcheaters.com, says simply that the site's customers -- around three million people -- "are adults."
"I believe in people's freedom, they have the right to choose who they want to be, especially when it comes to sexuality," added Biderman. "I look at affairs having two components -- meeting someone and not being discovered. So everything I have done from the moment we launched Ashley Madison is to help with both of these two components."
"My role in this is to give you a safe environment to connect and communicate with other people. I don't get a bonus if you meet in a hotel room."
The corollary to the surge in adultery sites, however, has been an increase in products that enable suspicious partners to monitor the activities of their other halves. Whether it is spy cameras or phone apps which store text messages or track an individual's movements, there is an ever-growing technological arsenal available to those seeking to unmask the unfaithful.
Jeffrey Jurist, whose website SpyAssociates.com sells a vast range of surveillance equipment, said that individuals seeking to uncover adultery account for around one-third of the company's turnover.
"Greed, lust and fear are all high-growth industries," he said.