Alexa no better if worse than PR

I used to care a lot about my sites PR until seeing all the posts about how PR wasn't important, SE placement and traffic volume was.

Recently I saw a post where someone asked that a site have Alexa under 1 million. There was no mention of PR or traffic to the site.

Personally, I think Alexa ranking is even less authoritative PR.

I have 2 blogs that do okay for sales and 1 that barely makes any:

Blog 1: PR2 alexa 654,000 avg 500 visitors/day
Blog 2: PR2 alexa 1,217,000 avg 1,900 visitors/day
Blog 3: PR2 alexa 611,000 avg 250 visits/day

How can a site with nearly 4-8 times the traffic and very distinct key words in nearly every search engine do worse? What exactly is alexa looking at? Why do some webmaster prefer alexa? What other options for a quick overview of a site exist?

They sure love to keep us off the chart... No way to figure them out.

alexa is all about people having a toolbar installed and surfing the net. Not he best way to compare sites and get reliable stats...