Anyone can sign up to Facebook or Twitter - but there is one social network where it's a little harder to get in.
ASmallWorld is an online club that recently kicked out Tiger Woods and Lindsay Lohan for being “wrong,” according to reports.
Described as “Myspace for millionaires” when it launched in 2004, ASmallWorld’s membership is capped at 250,000 - and you have to be invited to join.
This weekend, ASmallWorld relaunched as a paid-for club devoted to the “luxury” lifestyle - with a star-studded event in Morocco attended by Poppy Delevigne, Jasmine Guinness and Daft Punk.
The relaunch means that ASmallWorld will also - unlike Facebook and Twitter - have no adverts, with users paying $105 per year instead.
The network will also be policed to ensure it's free of "fake" profiles - a problem that dogs both Facebook and Twitter.
"We were initially built on the idea of exclusivity for the sake of it," says President and CEO Sabine Heller, 36. "But I think that is a subjective concept and not a sustainable one.”
The site’s decision to charge a subscription fee means it is unique among social network - it won't rely on advertising to make money from its "free" service.
"Facebook is selling tonnes of information to advertisers about user behaviour on and offline, so a lot of what we're doing is getting ahead of some of these problems and restoring an environment where our members feel comfortable," says Heller.
"Imagine if you lined up in a new city,” says Heller. “If you have your ASW membership card, there are, say, five hotels that are going recognise you and do something nice for you, or there'll be an event, a dinner, a cocktail event… you'll find groups of people based around common interest. You can turn on your mobile app and you can see there's aSmallWorld member 100 metres away from you.
"We have hundred of partners," says Heller. "I'd say we have over a 1000 hotels around the world who are giving our members incredible deals, rates, access and free spa treatments."
The app bombards users with deals, Heller says. She challenged two app users to fly to BUenos Aires with the membership card and app. A stay at the Mandarin Oriental materialised near-instantly.
"We have an apply for invitation process but we've honestly yet to invite anyone through that mechanism," reveals Heller. "We'll keep it as an option, but you always have to be invited in by someone you know."
"It's not about wealth, it's about trust and the invitation process is there to preserve the trust element. If I invite you in I'm accountable for you so if you misbehave you get chucked out and I get chucked out. The invitation process gives some accountability - which is important if you are travelling to Rio and meeting up with a stranger at 10 o'clock at night."