There are perhaps missing details, but Guifi seems to have "become" a provider by having "enough" customers. They got a peering connection. There's a threshold

There are perhaps missing details, but Guifi seems to have "become" a provider by having "enough" customers. They got a peering connection. There's a threshold beyond which peering make more sense than transit... (http://packetpushers.net/transit-vs-peering-makes-sense/ http://packetpushers.net/transit-vs-peering-makes-sense/).