As for the Bay Area, Silver wrote that either team had a slight but positive effect on the other:
Not much to look at here. Multiple choice--this is because (a) there’s a cleaner geographical distinction between the West and East Bays; (b) whatever Mapquest says, you couldn’t get from the Coliseum to SBC Park in 20 minutes if you were flying a Concorde; (c) Bay Area fans are characteristically non-committal and indifferent.
The last point is painfully true. Bay Area people are accustomed to having to drive an hour to get to work and at least 30 minutes to get to entertainment. I know plenty of Peninsula/SF people who never visit the other side of the Bay and East Bay folks who have little idea what the South Bay looks like. That begs the question, "How distinct are the four 'sides' of the Bay?" I've always thought it was a rather fluid dynamic because of the way I live, but maybe it isn't. Where does Fremont fit into all of this?
Elsewhere, Chris Isidore of CNN/Money looks at how scarcity is affecting ticket prices and demand. He noted that the average ticket price of an A's game went up 25% from 2005 to 2006. That number coincides with the newest Fan Cost Index numbers released by Team Marketing Report.
I'd go further into the FCI, but I'll save that for next week.