Groupon headquarters

Groupon, the funny little company that could and the fastest-growing one in history, prepares for its IPO and finds that a company's puberty is difficult, cutting its stated revenues in half after a complex back-and-forth with the SEC and some dogged accounting bloggers. In 2010, Marcia Froelke Coburn found Andrew Mason to be a wholesome, awkward boy-next-door; in Time Out Chicago, Frank Sennett captured the youthful, comedic vibe of the company. Less than a year later, Nicholas Carlson of Business Insider look a long, detailed look at what happens when a company simultaneously blows up and grows up:

"Working there was crazy," says another early employee. "[From 2009 to 2010] we hired 10,000 people.  That was completely insane — something that's never happened before, and should never happen again. We ended up in 45 countries in 16 months.  It was nuts, it was fun, it was a blast."

Photograph: Chicago Tribune