Use Glance to keep track of Alexa website rankings.
Track a website's daily rank against all other sites globally.
Track a website's daily rank against other sites in the same country.
How are Alexa Rankings Calculated?
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.
Read more at Alexa.com