last summer i bought a flat unidirectional line of sight 2.4ghz wifi antenna and mounted it outside my window facing a city park. i setup a limited bandwidth guest network that left my internet only access wide open from 9am-6pm, then I ran an IP sniffer on my PC to see how many fresh local MAC:IP's my router's DHCP would assign.
tested it could deliver at least 5mbps down across a 300'x200' park filled with toddler parents and high school kid all using smartphones. I only got a dozen unique users over a 3 month period, and only 2 of them were regulars who used it weekly. my area has RCN TWCable and FiOS fighting over wired, and lots of roof cell stations.
What I learned from this is even if a meshnet was available, most people are already conditioned to use their home/office/coffeeshop/transportation wifi, and their digital cell plans everywhere else, so it may simply be too late for a commercial meshnet anywhere but the most ISP/Cell under served areas.
this summer 2016 i may try again - this time using an inline signal booster to see if more speed attracts more leeches