Recently I was in a hotel that had dedicated indoor cellular 3G coverage on the lower floors. Dedicated in this case meant that one mobile network operator installed indoor coverage with antennas distributed throughout the hotel. So I would say that most foreign visitors sooner or later landed on just that network as the other networks had only weak or no coverage at all. And despite roaming prices having come down in recent years I think calls from foreigners are still highly lucrative. So I wonder who paid whom for the indoor coverage? Did the hotel pay the network operator so guests have reception in all places where outdoor coverage is weak or is the mobile network operator paying the hotel for the opportunity to get (more or less) exclusive access to foreign visitors? I'd speculate that it's the later but that's just a guess on my side. In any case, good cooperation from both sides to make the customer happy.