Likewise IAP that don't affect gameplay seem to me to be a fairly innocuous way to monetise your player base too, but they probably only work well in multi-play

Likewise IAP that don't affect gameplay seem to me to be a fairly innocuous way to monetise your player base too, but they probably only work well in multi-player games where they tap into people's desire for individuality and display. Valve has become a master at this of course, even if they did almost stumble into it by accident when they starting making TF2 hats. They're going down the same route with DOTA2 IIRC.