Q&A: Surely there can't be much demand for this?
Q. Ashley Madison - some kind of shoe designer?
A. A sensible guess, but definitely wrong. Ashley Madison is a dating website aimed at people who are already married. The service brands itself as "discreet", and simply picked two popular American girls' names as the company name.
Q. Wait - so they're a dating service for adultery? Isn't that immoral?
A. The company motto is: "Life is short. Have an affair."
The website offers affair guidelines, with advice on how to cover your tracks. So yes, it's immoral. In its defence, chief executive Noel Biderman says that someone wouldn't go to Ashley Madison unless they were already planning on having an affair. The website simply means that they won't cheat with a colleague or close friend.
We should see the company as "a safe alternative", he says.
Q. Surely there can't be that much demand?
A. Think again. It currently has 34 million members in 46 countries, including South Africa, Japan and South Korea.
Ashley Madison is planning to launch in Russia, Ukraine and the Baltic states in the spring.
There are 1.2 million people signed up to Ashley Madison in the UK, which is equivalent to around 5pc of the UK's married population.
Q. Sounds like the world's worst-kept secret. How long has it been around?
A. Ashley Madison has been helping adulterers unite since 2001.
Q. And how does it actually work? I'm asking for a friend.
A. Users don't pay a subscription to search, but have to pay to send other Ashley Madison members messages or virtual "gifts".
Each profile explains what they're looking for, which can be as specific as "bubble bath for two, gentleness, sensual massage" and far more explicit examples, which we won't mention here.
Users also state whether they're looking for a cyber affair, long-term relationship or short-term fling.
Around 70pc of members are men - no surprise there. Ashley Madison will make sure nothing incriminating comes up on your credit card bill, and members are free to chat and arrange meetings themselves.
Q. Thanks for that. I'll tell my friend.
A. You don't have to be so po-faced about it. As Noel Biderman said five years ago: "I can't worry about people thinking I'm a ghoul, because I'm pretty sure that history will treat me differently. It's 2010, people: time to redefine morality." (© Daily Telegraph, London)