But if I'm going to find out what really makes these women tick, I need to leave the safety of the virtual world and see them for myself. I arrange to meet a 41-year-old mother of two who misses "romance and flirting", in a cafe in two days' time.
Reading it on my laptop in the aptly named Cafe Affaire in central London, I consider what she really wants: a no-strings-attached sexual relationship.
Many of them are middle-class, many have young children.
And all of them are looking for an opportunity to betray their spouses. But I wanted to find out what sort of woman uses such a site.
I reply, telling her to come over and ask me face to face. She looks furtively around and asks me if I'm nervous. There is tension in the air like North and South Korea coming together to hammer out a treaty.
Suddenly the realisation of how odd it is to meet a stranger with the express intention of having an affair dawns on me. It's more like Alan Sugar interviewing an apprentice.