LivingSocial, one of the two most prominent social buying startups in the United States, has decided to expand to the United Kingdom through organic growth. The company’s opening a London-based version of the site and plans to open to a number of other big British cities over the next year.

Unlike Chicago-based rival Groupon, which landed in Europe through a recent acquisition of German clone MyCityDeal, LivingSocial is going on its own.

Social buying sites have been growing at a rapid clip, with at least 90 variants in the U.S., according to Yipit, a deal aggregator that tracks dozens of these startups. The model is relatively simple. The company posts a deal that’s available for just 24 hours. Usually, it’s a service at a local business like $25 for $50 worth of food at a neighborhood restaurant or 50 percent off a spa treatment. If enough people sign up for the deal, it’s on. There are also built-in viral mechanics; the deal might be free for someone who successfully refers three friends, for example.

LivingSocial is one of the biggest players in the space with $44 million in venture funding from investors including AOL co-founder Steve Case. The leading rival, Groupon, has just over $170 million in funding.

LivingSocial most recently raised funding in April, with a $14 million third round of financing, and says it has 85 million users.