Web Search Trends Follow the Flu

Apparently, Google has figured out a way to track flu outbreaks faster than the CDC:

There is a new common symptom of the flu, in addition to the usual aches, coughs, fevers and sore throats. Turns out a lot of ailing Americans enter phrases like “flu symptoms” into Google and other search engines before they call their doctors.

That simple act, multiplied across millions of keyboards in homes around the country, has given rise to a new early warning system for fast-spreading flu outbreaks, called Google Flu Trends.

Tests of the new Web tool from Google.org, the company’s philanthropic unit, suggest that it may be able to detect regional outbreaks of the flu a week to 10 days before they are reported by the Centers for Disease Control and Prevention.

Sure makes sense to me, but I wonder what else we could learn from search patterns. Why, for example, is the number one search term as I write this ” campus martius of rome ?” Is there something going on at the Pantheon that I’m not aware of?

Update: Here’s why “Campus Martius” is such a hot search item at the moment.