Google WiFi patent applications
Free WiFi served up by Google? Check out the following patent applications by Google:
(1) Method and system to provide wireless access at a reduced rate
(2) Method and system to provide advertisements based on wireless access points
(3) Method and system for dynamically modifying the appearance of browser screens on a client device:
You can read about the patent applications in more detail here. If free Google WiFi materializes with the only con being privacy inline advertisements, would you drop your normal connection?

Can’t see any reason why a good ad-blocker would not work, in any way the ads are served. I have not seen an ad in month. Adblock+ Adblock Filterset.G. Those are not even hard to use.
Wifi should be like water and air. Free (or ultra cheap) Think of it as a public service.