Overview of how an ad network operates, aggregating sites and selling at a lower cost.
Conversely, ANs undercut the big dogs in precisely the same way they help companies with small budgets. If a site sells its adspace at $50 per 1000 impressions, ANs sell across a broad set of sites at $4 or $5 for the same number of clicks.
Filed under: Advertising Business Model

Great info I am learning here.
Great thanks
hannry.chan@penzoft.com