The Alexa Traffic Rank Numbers get updated today. The Amazon.com's Alexa which is now supported by Windows Live, instead of Google has updted its Traffic Rank Numbers because of the fact that it would reflect estimated site traffic over Februray, March & April.
The amount of press Alexa has attained through the Microsoft & Amazon.com search partnership has made Alexa and A9 toolbars grow upto a certain extent though. Alexa,however is totally dependent on those type of sited which are related to the web marketing, SEO, advertisng and Webmaster world. Apart from this it is still considered as the only site traffic ranking systems on the market.