Many search marketers only look at online results and metrics, but there is more to search than just analytics.

CMO Magazine has an article that talks more about the importance of external factors to a marketing campaign.

Basically, news about Paris Hilton's latest escapade could give you a spike in clicks, and costs, if you manage any search campaign dealing with Paris, France or even Hilton Hotels, Hilton Head, etc. Being aware of these factors can help you manage your search campaigns and be prepared to capitalize on external events rather than be hurt by them.