Why are impressions free in Google AdWords advertising?

Contrast the PPC model to all other traditional advertising  models like TV,Radio,Newspaper, Billboard or even Direct Mail. You pay for impressions (or potential views called Cost per Mille РCPM ) without really knowing if your prospect actually saw your ad.

Product protocol: why it matters in innovation

Product protocol also called product definition, product requirements or product deliverables is critical to innovation. A product protocol is necessary after you have chosen a new product concept, completed concept testing and done some preliminary sales forecasting of what numbers you expect to sell and at what margins.