An interesting piece by Julien Le Nestour from Schlumberger on pricing social applications for the enterprise market. He argues why the usual volume discount approach to sales actually doesn’t reflect the way value is derived by the customer when it comes to social computing products, who, thanks to the network effect, gain value per seat the more employees participate.  So the argument goes: price low, or give for free, the first x nr of seats, secure adoption, then increase cost per seat with uptake and as value starts to show.  So in a way volume discounting in reverse (what’s that termed then?) 

There’s more to it than that, and reasons why life might not quite follow model, but a good article and worth a read.