There's been quite a bit of talk around our office about Alexa, and being the only web guy, I kind of chuckle.
Alexa recently changed the way they do things to counter the complaint that they don't really rank websites, they only rate how many times people with their toolbar hit websites.
http://www.alexa.com/site/company/announcement
I don't know exactly when they made this change, primarily because I don't really pay attention to Alexa, except to explain to the people in my office why I don't pay attention to Alexa when that person comes to me in a tizzy excited that some competitor has a better ranking.
Whoopdi-doo.