We have met with a number of companies in the online ad market recently. Every time I ask the entrepreneurs to chart how what they offer fits in with the networks, exchanges, data providers, ad servers, optimizers, agencies, etc. Inevitably, every one draws themselves in the center with the other players revolving around them. Also inevitably, the picture gets complicated rather quickly. Then this morning, I had a conversation with a friend who is on the publisher side. She was telling me abo...