If you have never heard of Alexa ranking before you are not necessarily in the minority. Alexa is a tool used primarily by techies but is catching on quickly among the general population using the internet. Alexa is a very powerful tool of viewing and comparing web site traffic for one site to the rest of the web. Basically, Alexa says this is the most visited site on the Internet. But what is Alexa and how do they rank sites?

Alexa is a company owned by Amazon.com which has as its main purpose to improve web navigation through participation from its users. Alexa does a lot more than simple rank web sites; they also have data services and webmaster services designed to improve the web. However, the focus of this article is Alexa’s Ranking system.

First, to even view a ranking on a site you must either go to www.alexa.com and type in the site you want information about or do what the majority of people do: install the Alexa toolbar onto their browser. When you install the Alexa toolbar on your browser any site you visit displays its Alexa ranking on the toolbar. You can simply click on this ranking (a number) and you will then be directed to Alexa’s website where you can view more information about the website including reviews posted by users and viewing a detailed traffic analysis for the site. But, the most important aspect of installing the toolbar is not that you can view the ranking of a site easy, but that when you install the Alexa toolbar every site you visit is monitored by Alexa and recorded. Now, Alexa is not keeping tabs on you, but this is how they rank sites.

When you have the Alexa toolbar installed every site you visit in a given day is given a vote for that day. If you visit a site multiple times during the day you visit is only counted once. Alexa, however, doesn’t stop there; it watches how many pages you view on that site and records that as well and will continually count the number of pages you view throughout the day (however viewing the same page over and over will only count once). Alexa calls the counting of each visit “reach” and the counting of page visits “page views.” Every day Alexa takes these two figures, and the figures from the last three months and calculates the traffic rank for each web site by applying a geometric mean (i.e., math) calculation to them. From these calculations Alexa ranks sites. The ranking is from the number one site (ranking one) to as many sites as there are. The lower the Alexa ranking number the more heavily visited the site.

What is interesting and advantageous in looking at Alexa rankings is that Alexa rates a site for the traffic which has visited over a period of months. This gives a stable realistic view of a site measure of traffic and how it ranks compared to other sites. By using a three month period the Alexa rankings are less subject to manipulation or by a one time spike in page views. Now, it is not perfect. Alexa only calculates for websites in their database because in order to get counted a site has to be visited by someone with a toolbar installed. And everyone doesn’t have a toolbar installed. So there may be a site visited every day by thousands of people not in Alexa rankings. But, it is probably very rare. Just looking at the top sites you can see that the heavily used sites on the Internet are ranked very low in Alexa. Here are some samples: amazon.com (rank 14); weather.com (rank 64); cnn.com (rank 26); google.com (rank 5); Yahoo.com (rank 1). These rankings are generally consistent with the amount of traffic they have.

Now there is quite a bit more to Alexa and Alexa rankings but this is enough to get you started. But, when someone mentions they have an Alexa ranking of xyz or they say they are the most visited site on the web you now know what is going on.

Source: e3servers.com