Re:I think your estimates are way too high (Score 5, Interesting)

I don't even think the coffee shop would need to charge anything for it - no tip jar or anything. I go regularly to a cafe in my city (SF) which has free WiFi. The cafe is nearly always comfortably full - not impossible to get a table, but most seats are taken. Meanwhile, other cafes around town which charge for access or have no access at all are nearly empty during a weekday. I think the increased business from having the service would pay for itself in one or two days of extra sales. You could argue that WiFi encourages people to sit there for hours on 1 coffee, but personally if I'm there for a few hours or more I get a sandwich and a cookie in addition to my 2 drinks, which I would never pay for at this coffee shop otherwise.