I think it'll end up being far more niche than most might expect. There's enough free wifi out there to be found. People would simply wait if they couldn't get phone signal or a free hotspot.
Exactly! And nowadays smartphone contracts are cheap. I have seen one for 1GB LTE, Flat Internet, Flat Phone and SMS for 15€. I mean who needs paid wifi anymore?
Having said that captive paid wifi in places like hotels can be outrageously expensive. You could sneak a router close to the premises and clean up.
That is very correct. The hotels mostly only have such standard contracts with ISP's and those are paid by the minute and very expensive. It's no fun using them. Having a free or cheap wifi in place is nice then.
But point one applies. It's too seldom that a free or cheap wifi is there. That's why users mostly will chose a smartphone contract. Available everywhere, even when it would cost. On the other hand, maybe the paid wifi will cost more, for the same bandwith, than the smartphone contract?