In the same year that a major motion picture chronicled (or lampooned, depending on your point-of-view) his college exploits, Time Magazine named Facebook founder & CEO Mark Zuckerberg the 2010 Person of the Year. Meanwhile, having just rejected a reported $6 billion purchase offer from Google, Groupon founder Andrew Mason blithely deflects questions from the Today Show’s Matt Lauer with an aloof mix of nonsense and non sequitur. Neither is yet 30 years old. Both are presumed billionaires. Who ARE these people? Are they the same or total opposite?

In the run-up to The Social Network, I devoured just about every piece of information I could regarding Zuckerberg and the founding of Facebook, as a means of checking the film from a fact-or-fiction, a Hollywood vs. Reality standpoint.

Likewise, as Groupon entered the local market, uncoincidentally at the same time as major competitor, LivingSocial, I dug into the background of Mason to see if there was another genius college dropout turned visionary CEO story afoot. I can tell you this much with certainty: Mason is no Mark Zuckerberg. Andrew Mason, for his part, does demonstrate clarity of vision, an underrated if unheralded virtue among the young CEO set.

But if you read the biographical profile found in the August 2010 issue of Chicago Magazine, you get the impression it’s Mason’s mentor, local serial entrepreneur Eric Lefkofsky, who is the real visionary. According to the feature, the roots of the whole Groupon idea came from a difficult divorce with a cell phone provider. Believing the angst generated by everyone who’s ever been through such a process could be focused into collective action and, hopefully, community remedy, Mason set to developing a non-profit organizing site called The Point. And while the site attracted a following, it wasn’t attracting investors. When it came to combine collective action with a money-making proposition, Groupon was born.

The rest, as they say, is history.

In tech years, Facebook is no spring chicken, as demonstrated by the fact that your mom, your dad and your grandparents have all figured it out. At a certain point, we’ve gotten to watch Mark Zuckerberg grow, not just as CEO of an indomitable Internet giant, but as a person, as an adolescent into an adult. Only 20 when he co-founded Facebook in 2004, we’ve seen or heard of him for so long, it’s hard to believe that the world’s youngest billionaire would barely be out of grad school had he taken the more traditional path.

A reluctant interviewee early on, Zuckerberg was considered arrogant and standoffish when defending both Facebook’s success and increasingly public missteps. But even as the slings and arrows of privacy concerns and backlash against site changes intensified, nothing has slowed the Facebook train as it cruised past the half-billion user milestone.

Meanwhile, the boy CEO has grown as well, recently appearing on 60 Minutes, ostensibly to announce yet another iteration of the Facebook interface. But what was really on display was a grown up Mark Zuckerberg, ready to put a real public face, not just for his company as they attempt to change and dominate the Internet, but for himself as well.

On the other hand, as a public persona, Andrew Mason seems to be regressing. A Nightline piece a few months ago showed the Groupon CEO as the easygoing boy-next-door his company profile describes, casually tossing out the accolades and reminding everyone that they’ve thrived as new and well-backed imitators spring up around the world on what seems like an hourly basis. Fast-forward to a more recent Today Show interview, where relevant questions were dodged like bullets and Mason’s squirmy, awkward responses indicated a discomfort with the trappings of sudden fame and riches.

For all the perceived arrogance, Zuckerberg has never seemed to shrink from the challenge of running the Internet’s biggest company. It would do Mason well to develop some semblance of that fortitude, or the CEO with the “fastest growing company ever” (according to Forbes magazine) may prove to be too great a mantle to bear.

Naturally, only time will tell the fates of both companies and their suddenly super-rich young CEOs. In a final comparison, it’s worth mentioning that some of Zuckerberg’s most awkward moments with the press were in deflecting buyout and lawsuit talks. Maybe when the conversation about Groupon turns away from Google’s offer and more to the company’s future, Andrew Mason will rebound and find the confidence and grace that Zuckerberg has shown. We shall see. And answer the question from the outset: Who are these people? They’re not like you and me, that seems clear. But while they don’t appear to be on the same plane at this point, it’s possible that they may find more common ground in the future.

Who knows, maybe it’ll be Facebook’s money that is ultimately too much for Groupon to turn down.

-Thomas (@thomasmcdonald)