One of the reasons Republicans have been mad about in these final weeks is "How did a unknown quantity like Obama trump a known candidate like McCain". Thats what McCain had been tapping into these weeks using the phrase "Who is the real Barack Obama?" When you take a look at the Obama campaign strategy and their heavy use of Ads through out their campaign, it becomes very clear how anticipatory the Obama campaign had been in their strategy. 

Very early even during the primary season it became apparent that only one candidate was new and unknown. If Obama didn't move quickly to define himself to the public others would do it for him, and in not so benign ways. The latest article in the Christian Science Monitor on Obama expenditure in Ads is making this effort on part of Obama campaign apparent. As the article quotes: