News CLICKYThat's quite an interesting concept.
The only issue I see is that in cities there are very fast phone signals as it is. However I could see myself using this in areas where 3G coverage is poor. The price of adverts may be worth paying if the difference between mobile and WiFi connection speeds is good enough.
For example: Eastmidlands Airport has a very slow phone signal. I'd like to use WiFi there, but the prices the airport charges for their WiFi is just not worth it. If this was available in places like that, I'd be very interested.