Do Londoners Spend More Money on Mobile Gaming?

I have just arrived in one of the few cities in this part of the world in which the metro (underground, tube, whatever you call it) is not covered by mobile networks. It's a sad state but maybe the mobile gaming industry is rejoicing as I noticed a lot of people this time using their mobile device, which has become utterly useless once they stepped into the underground for one of the few things that still work without the network: Offline gaming. But one could also turn the stick around and ask: As more people go online on their mobile devices, will mobile gaming revenues decrease due to people preferring to do things online rather than playing a game while commuting?