Google is reportedly interested in buying Groupon, for good reason: Groupon is growing insanely fast and seems to have cracked local online advertising, which could be hugely valuable to Google.

But here's how Google could destroy the deal.

If history is any indication, Google will probably try to change Groupon, to make it more Googly.

But the two companies have vastly different structures and cultures -- like oil and water. And based on our understanding of Groupon, Google could potentially ruin Groupon very easily.

Why? Because Groupon is primarily a sales and writing organization, built on people-power and smiles. It employs some 3,000 people around the world, most in sales, customer support, and editorial.

"I'm not sure this is a tech company that gets built in San Francisco or Palo Alto," Groupon cofounder and CEO Andrew Mason told us when we visited his office last week. "It's so heavily people dependent -- not really consistent with the way people think about building startups in the Valley." (Mason refused to discuss anything Google-related, and did not deny the talks.)

In Groupon's bustling 1,000-person Chicago headquarters, heroes include comedy writers, improv actors, and buzzing rooms of salespeople. There is an office elaborately decorated as a bedroom for an imaginary, deranged tenant. It's hilarious, but also the kind of thing that the brains at Google probably wouldn't find funny, or support.

Google, meanwhile, is the master algorithm. Yes, there are lots of people at Google, too, including many sales and support staff. But Google's culture is dominated by engineers, the sort of high-GPA geniuses who can answer all of the brain-teaser Google interview questions, and by the image of being clean and non-evil.

Sure, it's possible that Google could promise Groupon complete autonomy, with the freedom to maintain and grow its counter-culture, and to hire its staff the way it always has, with Google's assistance mainly for infrastructure and investment. YouTube is sort of like this, even 4 years after being acquired.

DoubleClick, on the other hand, was swallowed whole, and quickly Google-fied. Same with pretty much every other Google acquisition, large and small. And that's the sort of thing that could totally screw up Groupon.

Don't miss our photo tour of Groupon, the funniest startup we've ever been to →