I think it's hard to find an objective measure, given that there are so many franchise fans that solid sales are basically a given - I wouldn't expect to see the consequences play out until D4.

That said, the fact that they rebuilt the absolute core gameplay loop - loot collection - to incorporate a real-money auction house, and had to roll it back, speaks volumes. Business-people do not abandon a monetization strategy unless it's proving to be costly in unintended ways.