Alexa ranking mechanism detailed-alexa world rankings

Introduction
Know Aelxa webmaster is more and more, but recently I found that many webmasters did not carefully read the Alexa report, but only to see a number, is ranked. In fact, many times, the other two data provided by AELXA-the number of clicks per million and the number of page views per person-are more worthy of study.
Alexa sources of data
Although it is almost universally known, it must be emphasized that Alexa's statistics come from their collection of Web site information accessed by Alexa toolbar users, that is, only when a Web site is "installed and using the tool bar" access, AELXA will know, otherwise, How can aelxa know when a person visits a website in his own home?
Obviously, if a person does not have the toolbar installed, or installed but not used (such as shut down or he temporarily use another browser), then he visited any site will not be Alexa know.

In the following text, I refer to "the person who installs and uses the Alexa Toolbar" as "Tool bar user".

Understand the number of clicks per million people (reach million users)
We first cite such an example, a B two people work in two companies, a said: Our company has 100 people know me, B said: Our company has 200 people know me. So who is more famous in his own company? No way to judge, because we do not know how many of their respective companies, if a company total of only 100 people, and B's company has 500 people, then it is obviously a more famous in their own company (all people know him).

Alexa is the same, because the number of toolbars per day is not the same (every day have installed or uninstall, the installation of the tool bar is also not the time of the Internet), so if the Alexa show the actual number of clicks is not conducive to the contrast between two days.

For example, yesterday, 20 toolbar users visited your site, today or 20, you will think that the popularity of your site is unchanged, in fact, because these two days the Total toolbar user is different, if yesterday is Thursday today is Friday, today the total number of Internet users increased a lot, The number of people who visit your site does not increase, which means you are a step backwards.

So Alexa introduced a "number of clicks per million users" this parameter to more scientific measurement.

For example, there are 500,000 active tool bar users today, 50 of them visited your website, which means that one out of 10,000 of people visited your website, so if there are 1 million people, there should be 100 people to visit your website, so Alexa will show you the number of millions of users clicks is 100. And if today there are 2 million active toolbar users, 50 of whom have visited your site, the same method calculates that the number of millions of users clicks should be 25.