To paraphrase Bob Dylan, Rush Limbaugh is not my cup of meat, but I have to salute him for making the free enterprise system work for him, to the tune of a $400 million contract extension for the next eight years. That’s a pretty dang enormous deal for one guy, comparable only to Howard Stern’s deal for $500 million for five years at Sirius. (Plus, Stern has to pay his show’s labor and production costs out of his own pocket.)

Now, I know a lot of people are scratching their heads over this, since $400 million seems like quite a gamble for Clear Channel to spend at a time when its own revenues are declining, and on a guy with a well-known history of health problems (including deafness and drug addiction) and whose conservative shtick seems to be going against the prevailing political winds. But I think it makes business sense for a few reasons.

First, the coming election results won’t matter a whit to his ability to do what he does best: work up an outrage over politics. He’s dissed both Obama and McCain in the past, so whoever wins, he’ll still get to play the aggrieved victim. Second, the size of his listenership doesn’t really matter. (It’s been estimated at between 14 to 20 million listeners a week on 600 stations; in any case, no other radio personality comes close to his numbers.) For the last 20 years, he’s had a loyal core of “dittoheads” who’ll follow him whether his ideology is in the ascendancy or on the wane. A station that puts Limbaugh on the air figures it can build an entire slate of like-minded talk shows around him, figuring that if his listeners will come for him, they’ll stay for the rest.

What’s important, from an industry standpoint, is Limbaugh’s ability to deliver those listeners to advertisers. In the fascinating profile of Limbaugh that runs this weekend in the New York Times (but is already available online), Limbaugh says that he’s a businessman first, and his priority is to sell airtime. What’s more, the big-ticket sponsors who advertise on his show know it’s a friendly environment for a pro-corporate, consumerist message. “I consider myself a defender of corporate America,” Limbaugh tells the Times. In other words, no sponsor ever need worry that its ad will appear alongside a rant about downsizing, pollution, price-gouging, or other corporate bad behavior. (This is also, conversely, one reason why liberal talk radio hasn’t prospered: sponsors are afraid to support what they fear will be a hostile environment for their ads.)

Finally, it’s probably worth it for Clear Channel to pay him an exorbitant sum of money (and to let its competitors know how eager it was to break the bank to satisfy him) than to risk losing him to another radio network when his current contract expires. In fact, maybe the big windfall is a signal to advertisers that Clear Channel (whose radio revenues dropped $30 million in the first quarter of this year) and radio itself are still strong and viable. After all, they can afford to pay this guy $400 million — and he’s just the help.