Maybe Groupon wasn’t quite so dumb to turn down that 6 billion dollar offer from Google a while back. The increasingly popular group coupon site has filed to raise 950 million in venture capital money based on a valuation of 6.4 billion dollars. It’s looking to get bigger faster and already employs 3000 people. It hasn’t really gone mainstream yet, still seems to be a lot of trips to day spas whenever I look at it, but maybe 2011 is the year that it joins The Tech Pantheon of Inescapable Companies. Meanwhile, Groupon now makes up 79% of group buying in the US, far ahead of Living Social, one of its rivals, although it really has no rivals at this point.