Have you heard of Alexa? No? Well, don’t feel shy if you haven’t, because many others haven’t either. But Alexa is catching up quickly among the common internet users. Alexa gives rankings to sites, and is an extremely powerful tool which can compare the traffic of a site to the rest of the web. Alexa, a brand owned by none other than Amazon.com, gives rank to a site by help of the participation of its users. Alexa does more than just ranking sites. It has webmaster services and data services as well.

To view the ranking of a site you can either go to alexa.com, and type the name of the site, whose rank you want to see, or else install the Alexa toolbar on your browser (the latter is more common and convenient). After installing the Alexa toolbar, you can see various numbers on the toolbar, as you visit various sites. These numbers are the rankings of the sites. The lower the number, the more visited site it is. For example Yahoo ranks no1, Google no5 and Amazon.com no 14; quite obviously meaning yahoo is the most visited site in the world.

 How does it work? Whenever you install the Alexa toolbar on your browser, it starts monitoring all the sites you visit; using the data to rank the sites. As you visit a site, Alexa casts a vote to that site for the day. It however does not give more votes to the same site if you visit it several times during the same day. It also goes ahead and monitors how many pages of the same site you visit, and will add up the number of pages you visit during the day (again, it does not count the same page twice, if you have visited it twice). The counting of each view is called reach, and the counting of page visits is called page views. Alexa uses both these figures, and uses the same data for the last three months to calculate the traffic visiting a site.

 The good thing about Alexa rankings is that it uses the data of three months to generate rankings. This means there is less chance of manipulation of ranking over a short period. The bad thing is that Alexa rankings are not perfect; since they show rankings based on the data generated only from Alexa toolbar users. This means, if thousands of visitors who are not using the Alexa toolbar, visit a particular website, the site’s high traffic data will not reach Alexa, since the visitors were not using the Alexa toolbar.