Alexa - Much Value

[Markz]

The Alexa ranking means very little as they only go on data they have from users who have the tool bar installed so how can it be accurate at all.

I think it used to be rated but not now.

[escapeso]

What do mean it used to be rated? Did Alexa used to be more accurate?

[montenegro.offplan]

Alexa rank is not always correct and objective.
How I will look my page rank online?

[REW Reed]

The thing is, unless you had a way of tracking every single page request across the entire internet, there is no way to feasibly get 100% accurate data. Unless every website on every server everywhere ran Google Analytics or some such and reported back to a central database, there would be no way to even get above 50%.

Now, statistically you only need a good random sample of people that represent a cross section of all of the internet users to be able to produce remarkably accurate trends. Statisticians have been using this principle for years to accurately gauge people's interest in various forms of media. Nielsen Ratings are a great example of this. Although both Alexa and Nielsen Ratings are inherently flawed by not being truly random, the information they present has quite a bit of accuracy.

Alexa and a few others mentioned in this thread, as well as tracking systems like Google Analytics, provide quite a bit of information about the traffic coming to your website, but there is no end-all be-all for comparing different website's traffic.