Daily deals site Groupon has filed for an IPO, offering up a possible early payout for Seattle venture firm Maveron. According to Groupon, via a filing today with the SEC, it is looking to raised up to $750M in an IPO under the symbol GRPN. The IPO is being underwritten by Morgan Stanley, Goldman Sachs & Co., and Credit Suisse. If successful, it would be a quick turnaround for Maveron, which acquired 949,668 shares of Groupon's stock in February of this year, and added Maveron and Starbucks founder Howard Schultz to its board. According to the S-1, Maveron paid $17.2M for those shares, which it used to cash out some other shareholders in the firm.