In my conversation with Chris Anderson, he mentioned in passing that free was as cheap as things can get. I answered that no, you can actually go lower than free. You can pay people to use your product, what is essentially a negative price, better than charging zero. Someone must have been listening. From the WSJ :
Microsoft Corp. hopes to make gains on Google Inc. in the lucrative
business of Internet search through a new service that pays consumers
who buy items they find through the software company’s search service,
according to people familiar with the company’s plan.
Redmond, Wash., software maker is rolling out a service called "Live
Search cashback" that gives consumers money back on certain purchase of
products found through Microsoft’s live.com Web search service, the