Groupon revealed that the startup\'s chief operating officer was leaving after just five months for a job at her former employer -- Google. Margo Georgiadis quit for a post as president of the Americas for the California-based Internet giant.Georgiadis was vice president of global sales at Google before leaving in April to work at fast-growing daily-deals hotshot Groupon. \"Groupon is a great company and I feel privileged to have worked there even for a short time,\" Georgiadis said in a note released by Groupon on Friday. \"It was a hard decision to leave as the company is on a terrific path,\" she continued. It is the second time this year that Groupon has lost its chief operating officer. Turnover among executives has been cited as part of the reason the startup has delayed an initial public offering of stock (IPO).\"As a fast-growing company, we\'ve done a lot of hiring this year, including on our senior executive team,\" Groupon said in a blog post. \"It would have been great if I could say that we batted 1,000 percent, but that\'s rarely the case,\" it continued. Groupon has seen tremendous growth since it was launched in Chicago in November of 2008. Revenue climbed to $392.6 million in the second quarter of this year from $1.2 million in the same period in 2009, but the company posted a net loss of $101.1 million as compared to a minimal profit of $21,000, according to IPO paperwork filed with the US Securities and Exchange Commission.In the same two year stretch, Groupon expanded into 170 new North American markets and 45 countries, according to the filing. The number of Groupon subscribers grew from 152,203 as of the end of June 2009 to 115.7 million at the end of the second quarter this year, SEC paperwork indicated.