After months of speculation, and even some on-stage dodging during an interview at the D: All Things Digital conference, Groupon has filed for an IPO.  The development marks one of the most high-profile IPOs of the year, especially after Groupon turned down what would have been one of the most high-profile acquisitions by Google.  Groupon’s looking to raise up to $750 million, with Morgan Stanley, Goldman Sachs and Credit Suisse as the lead underwriters.

Groupon’s been a breakthrough Internet company, gaining large scale traction and attention with its discount service through online deals.  The company pulled in $644 million in revenue in Q1 2011 alone, up from $3.3 million in Q2 back in 2009, and $44 million a year ago, reports The Wall Street Journal.  But even with these high numbers, Groupon lost $102.7 million in the first quarter, amidst lots of bubble talk and questions regarding Groupon’s effectiveness as a localized marketing tool.

Nevertheless, Groupon’s revenue has grown nearly 20,000% since June 2009, less than a year after launching its service in 2008.  The company boasts upwards of 50k local merchants across 43 countries, selling “Groupons” and taking a cut from each sale.  Global expansion has warranted thousands of new employees for the Chicago-based startup, the bulk of them filling out Groupon’s sales team working directly with merchants.

Just days after LinkedIn’s IPO, Skype’s acquisition by Microsoft, and Fusion-io taking its flash memory company public, Groupon’s initial filing is the latest in a string of IPOs, heightening the bubble talk even Marc Andreesen, who’s venture firm is also a backer of Groupon, is trying to downplay.  As you can see, the types of tech companies looking to go public is varied, especially when you add Zynga and Millennial Media to the mix.  Facebook is the company that would trump all of these IPOs, though the social network says it won’t go public until next year.