Read this article which really made me think:
http://gyrovague.com/2013/06/05/time-is-...-app-purchases/TL;DR version:
"What this means is that, once your bankroll is over 1.5 million or so, the only free way to keep the balance growing is grinding, a tedious non-stop cycle of raiding and army rebuilding, with nervous logins every five minutes to keep raiders at bay (you cannot be attacked while online)."
I've never played Clash of Clans, but it seems the entire concept is based around raiding. I'm not saying this is your typical "PVP" where skill is involved, but it's interested to see a business model based on pillaging making a comeback in the mainstream. Sounds like a good sign for game developers who were always worried that the common gamer isn't won't play a game where they may lose their hard earned purples.
Anyone ever played it?