Mac might be slowly gaining on Windows but it's a very slow growth.

That San Franciscans use more Macs should be a surprise to no one. Their salaries are a lot higher than people on the east coast (a few choice cities excluded). Of course their living expenses are a lot higher too; but computers cost the same no matter where you live. $1200 to a San Franciscan is a different type of purchasing decision than to someone from, say Ohio. In San Francisco $1200 is a month's rent on a studio apartment. In many parts of the east coast that's a pretty luxurious 3 bedroom condo.