Ashley Madison operates in 50 different countries, in 17 different languages.

Ruben Buell, the company's director and CTO, said cheating isn't something that happens once in a blue moon.

Even after the data breach in 2015, people keep coming back to the site.

It's a better way to have an affair, said Buell, because you're guaranteed discretion.

"It's just human nature," he said.

If you sign up to Ashley Madison, you don't have to think about what you're doing as cheating, but "outsourcing your sex life."

"In 2018 we expect our life partners are going to be everything to us — they've got to be my best friend, they've got to be sexually compatible, they have to be great at coparenting," Ruben Buell, Ashley Madison's president and chief technology officer, told Business Insider.

"We have to have the same vision of finances, we have to have the same hobbies, the same interests... There's so much pressure on that one relationship, everything has to be right.

"And sometimes, the vast majority of it is right, but maybe there's something that's not."

This is one of the reasons Ashley Madison currently sees 20,000 new sign ups a day, and over 40,000 affairs happen on the site every day.

Even after the data leak back in 2015, people came back to Ashley Madison. Buell said the company had to focus on the security and privacy in the whole company after what happened, and now it realises how important it is to keep user information as secure as possible.

"It's the upmost importance to us, and I think the firm has done a really great job and really brought itself back to life," he said. "And I think the users see that."

Cheating isn't something that happens once in a blue moon. Shutterstock/ wavebreakmedia

Why they keep coming back

People don't generally cheat because they want to leave their relationship, he claimed, but to outsource their sex life.

Research from sociologist Alicia Walker last year found that women in particular "cheat to stay."

"They very much presented this scenario that their marriages are either completely sexless, or orgasmless — at least for the women themselves," she told Business Insider at the time. "They very much convey that: if I don't do something to address this, I'm going to end up leaving. I'm going to end up breaking up my family, breaking my children's hearts, breaking my husband's heart, and I just don't need that."

A fling isn't worth tearing a family apart, Buell said, so if cheating is going to happen it may as well be in a way that causes the least obvious harm.

He said Ashley Madison's main competitor isn't another website, it's the workplace. But instead of hooking up with a colleague, or meeting someone in a bar, he said Ashley Madison offers discretion.

It also means you're going to meet someone on the same page as you, and in a way, things are more honest from the get go.

"The community at Ashley Madison is a very open minded community, it's also one where you have less risk," Buell said. "It's actually contrary to what you think, because a lot of relationships at Ashley Madison start from a very honest place. So you have two people who really aren't trying to hide anything."

When dating traditionally, you can go out with someone four or five times before you start to show them your true self. But on Ashley Madison, Buell said, the flaws are all visible right off the bat.

"If a person is going to have an affair you should probably have a better type of affair," he said. And plenty of people are looking for something that Ashley Madison can offer, as "it's just human nature."

"We don't operate in 50 different countries and 17 different languages because it's a small thing that happens once in a blue moon," he said.

"I think at some point we learn that life isn't exactly the fairy tale we were told when we were little boys and girls. Life is real. Our average users are in their 30s in their 40s, they've lived life, and they've realised sometimes they've got to do something for themselves."