Back when Alexa.com started, before they became a toolbar to send traffic to Amazon, I used to visit them once in a while and wonder what all the fuss was about.
They clearly state that the numbers are only an estimate based on their users with toolbar installed… meaning that the majority of your readers aren’t counted.
Now Alexa ranking are quoted like gospel.. because so many other have quoted them.
Sure, there are a lot of those toolbars, and the trends are an indicator. I use the toolbar for a quick feel of where a online marketing company is.. as they are likely visited by those with the toolbar installed… but wouldn’t plan a campaign based on it. The numbers don’t apply to non-savvy users.
Now this story shows that the numbers aren’t being updated