Groupon files for IPO. Financials reveal bleeding red ink. Is the next great tech bubble forming?

Earlier today Mashable reported breaking news that Groupon has filed for a $750-million IPO, not long after LinkedIn’s wildly successful public debut last month.

Unwritten by Morgan Stanley, Credit Suisse and Goldman Sachs, the filing reveals Groupon’s financials: in 2010, the company’s revenue was $700 million, 23 times its revenue the year prior—an astounding number that has seen the Groupon called the “fastest growing company ever” by Forbes magazine. And in 2011’s first quarter alone, the company’s revenue was nearly $650 million, putting it on pace to crack $2 billion by year’s end—or, if factoring in its current growth trajectory, $3 billion.

Groupon now has over 80 million subscribers, already up dramatically from the 50 million it had at the end of last year.

All of this, and the company is not even profitable.

In fact, it’s incurred hundreds of millions of dollars in losses over the past couple of years and into 2011, and foresees rising operating costs for some time. It also has dozens, if not hundreds, if not thousands, of competing daily deals sites to contend with.

Then again, LinkedIn isn’t really much for profit either and is overshadowed by Twitter and Facebook… yet a lot of people made a lot of money when LinkedInk debuted on the New York Stock Exchange in May under the ticker LNKD and exploded to more than 150 percent of its opening share price (it’s price has since dropped).

Investors hungry for a piece of the next tech revolution? Hell yes. The beginning of a bubble? More and more say it’s so, but no one ever knows for certain until one bursts.

Whether or not a bubble is forming, Groupon—which turned down a $6-billion offer from Google, who subsequently launched a competing service—will be a telling factor with its IPO.

Andrew Mason, Groupon’s founder and CEO, wrote this in a letter to shareholders:

If you’re thinking about investing, hopefully it’s because, like me, you believe that Groupon is better positioned than any company in history to reshape local commerce. The speed of our growth reflects the enormous opportunity before us to create a more efficient local marketplace. As with any business in a 30-month-old industry, the path to success will have twists and turns, moments of brilliance and other moments of sheer stupidity.