Alexa’s traffic estimates and ranks are based on the browsing behavior of people in our global data panel which is a sample of all internet users.
Alexa’s Traffic Ranks are based on the traffic data provided by users in Alexa’s global data panel over a rolling 3 month period. Traffic Ranks are updated daily. A site’s ranking is based on a combined measure of Unique Visitors and Pageviews. Unique Visitors are determined by the number of unique Alexa users who visit a site on a given day. Pageviews are the total number of Alexa user URL requests for a site.
To start tracking you need Alexa Verification ID which needs to be verified for site Ownership