You can talk about HV's customer base shrinking if agents leave the market, but what is happening with the existing pool of agents? HV has got to be one of the most hated companies on agent message boards. Even if these are agents who were lazy and didn't use the system, there are little to no posts defending HV. The negative cloud that hangs over HV's head has got to be a problem for their long term success, unless they can change the way potential agent customers see them.
I wonder if agents were asked the following question:
"Do you think HouseValues.com is a good product for agents?"
I wouldn't discount agent message boards. Some of the good boards actually have great information flowing back and forth between agents. You can get a pretty good temperature read on products and services.