I'm mixing stories here: Om Malik speculates that Google's efforts to lease dark fiber and buy direct telecom capacity isn't just about them saving infrastructure money, but also about them reaching their users directly. He asks, what if Google gave Wi-Fi to everyone for free?
They might easily afford it. Besides their huge free cash flow and their huge GAAP-style earnings and their huge IPO, there's a secondary offering coming of INT((π - 3) * 100,000,000) shares to raise another $4 billion. With four billion more bucks, subsidizing Wi-Fi through the U.S. (or most of the industrialized world) would be a large line item.
But could it reap them enough return in increased ad dollars through localization? Probably not. It's better for them to let ISP's and WISP's and others run the end-user infrastructure, and bear all the cost and risk.