The Bay Area is a unique case, in that San Jose and Oakland had already chosen to remove fees; those two relatively small airports that have non-stop flights to long-haul destinations can provide Wi-Fi at likely a fraction the cost of the massive and sprawling SFO. But SFO may want to compete effectively against its two alternatives. Sacramento clearly chose to offer free Wi-Fi years ago to attract some travelers inland north instead of south to the bay.
I spoke to Boingo Wireless recently about the trend of free airport Wi-Fi, and Christian Gunning explained that while there's ongoing interest in operating Internet service by airports without charging passengers, the fiscal realities of a down economy and the costs of operations put this out of reach of most authorities.
Coupled with that, Gunning noted, free Wi-Fi brings with it substantially higher levels of usage that mean either increased spending for the necessary backhaul or disappointment in the quality of congested service.
Jordin Sparks joining Broadway showWith Starbuck’s Move and Widespread 3G, Who Pays for Wi-Fi at Hotspots?