It's currently growing at around 10% each week as it adds new users through Twitter and Facebook. The website offers users discount vouchers called 'Groupons' which give large discounts on retailers websites. Groupon sends its members daily e-mails with about 200 discounts for goods and services.
The deals are activated only when a minimum number of people agree to make a purchase, giving Groupon clout to negotiate steep group discounts on products. The deals expire unless enough people sign up. But despite being described by Forbes as 'the world's fastest growing company', Groupon is tiny compared with Facebook.
Groupon makes it money by taking a cut of each sale and has a projected turnover of $500million (£320million) this year. Owner Andrew Mason was also reported to have turned down a $2billion (£1.3billion) offer from Yahoo in April because it did not meet his valuation. His website provides up to 90% off products ranging from glasses to car hire and cinema tickets.
Commentators have described Google's potential purchase as a 'killer move'. Kara Swisher, from the All Things Digital website, said the deal will 'give (Google) huge troves of data about consumer buying habits and merchant information across the globe'.
Andrew Mason who has based his company in Chicago, has over half his employees working the telephones making sales with small businesses.The company claims it has saved Britons £52million and is currently the 69th biggest website in the country. The up-and-coming entrepreneur is famed for his sense of humour - and has claimed he owned over 200 cats. He said: 'Most CEOs will make stuff up about themselves to sound way smarter and cooler and people are disappointed to find out otherwise.
'I decided to set the bar very low and make up lies about myself that make me sound lame.'