Ad Type Context From The Economist

"Yet Google's latest deals contain a hint of weakness. Henry Blodget of Cherry Hill Research, a consultancy, notes that in its original business of placing text advertisements on its own search pages, Google makes profit margins of about 60%. In its more recent business of placing advertisements on web pages belonging to other people, such as bloggers, its profit margins are 10-20%, because it is harder to make the advertisements as relevant to the audience and it must share the resulting revenues. Display advertising also offers lower returns."


http://economist.com/business/displaystory.cfm?story_id=9040227


Amateur media, like blogs, and professional media, like The Economist, provide great symbiotic context for each other.