Alexa's rankings are based on the tracking data of the "Alexa Toolbar". It tracks its users' usage patterns of the Internet. It tells you how popular a website is.
Pages are ranked among all Alexa users in a rolling period of 3 months. Ranking stats include "Pageviews per User", "Bounce Rate", "Time on Site", "Demographics", "Clickstream", and "Search Traffic" of a website tracked.
Here are the top keywords searched by the users from the web which drive traffic to my website.
1/ comme ca ism
data source: www.alexa.com (as of 4th March, 2010)