At home, Mark Whitacre (Matt Damon) has a business line and a personal line. You should know that because the FBI does, and so do his bosses at Archer Daniels Midland ("Supermarket To The World"™). Mark is pretty good at compartmentalizing his life, but the lines are about to get crossed a little bit.
Mark lives with his wife and kids in Decatur, IL, but he's been all over the world with ADM and he's proud of what they do, especially with corn. They make all kinds of stuff out of plain old corn, from high fructose corn syrup to lysine to ethanol -- all of which, you might say, are fuel additives, designed to juice up production of... whatever.
Celebrating ADM's miraculous line of alchemical products, Mark excitedly notes: "Corn goes in one end and profit comes out the other!" Vivid image, that. Kind of suggests Mark's chronic logorrhoea, the stream of partially digested thoughts that swirls around inside his head and occasionally gushes from his mouth. When he gets going his internal monologue (in voiceover) actually talks right over his lips and his tongue. He doesn't interrupt himself; his mouth and his brain just keep spilling over each other. I wouldn't be surprised if Damon's Mark Whitacre had a cousin named Jerry Lundegaard in Fargo.