The alexa rankings need to be taken with a grain of salt, since they only account for those internet users who have downloaded the Alexa Toolbar. Are you aware of that? It means the #'s can be manipulated. That's all I can say about it, as I don't know how much of a disclaimer that means one should attach to the numbers.
Here's another example, and they mention Alexa also: (re: ranking.com) http://www.internetbasedmoms.com/seo/about-ranking-com.html "The rankings are generated through the users of the 7Search toolbar. Like Alexa, you will have to take Ranking.com's rankings with a huge grain of salt as they are not accurate and are based on the toolbar downloaded by users."
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