Legendary fund manager Peter Lynch once said that you shouldn't invest in any idea you couldn't illustrate with a crayon.

I'm not much for crayons, but I do love the pithiness of that line. We regularly preach the same idea at the Fool: Don't buy what you don't understand. And if you can't simply sketch out a company's business model -- how it actually makes money -- then maybe you shouldn't be investing in it.

Today I'd like to share a very simple visual of how Altria Group (NYSE: MO) makes money. (Note: I'm focusing on revenue here, not earnings.) Here's my attempt to encapsulate Altria's top line.

Altria

Numbers calculated using 2010 revenues, inclusive of excise taxes.

I've included the U.S. map because after its Philip Morris International (NYSE: PM) spinoff, 100% of Altria's sales are domestic. Note, too, that the company's large ownership stake in SABMiller isn't included.

When the company changed its name to Altria in 2003, the L.A. Times reported that "executives said the change will help to clarify the diverse nature of the company's businesses." Now that it has divested Kraft, Altria is just as much a Philip Morris company as it was when its name was "Philip Morris." Maybe even more so. (Read up on how "Marlboro Lights It Up for Altria.")

Think I missed something in this illustration? General thoughts on this exercise? Let me know in the comments section below. And if you haven't already, be sure to follow our Altria news and commentary using the Fool's free new My Watchlist tool.

Fool.com managing editor Brian Richards thanks his wife for lending him her design talent. Brian owns no shares of any companies mentioned. SABMiller and Philip Morris International are Motley Fool Global Gains selections. The Fool owns shares of Altria Group and Philip Morris International and has a disclosure policy.