After Alexa went through changes, now you can see more info for any website. One option that is very good is the keywords that drive traffic to your site from search engines.
However, if 100 webmasters who have alexa toolbars on the workstations (pcs) visit your site it gives you thousand times higher traffic rank than if you have 100 ‘ordinary’ traffic. Alexa is someway corrupted. And it will never change.