According to Alexa, they were working hard behind the scenes for several months to make more accurate rankings for sites on the net. This has changed the traffic ranks of some sites drastically. As Alexa is saying they now included more sources and improved methodology to present better rankings, in fact, it is not better ranking but more accurate ranking. This will be the correct statement. However, most of the bloggers have already noticed this change.
Our traffic went up from 178,000 to 128,000. This we expected and hope it will be within the first 50,000 sites very soon.
Here is a round value.
Sites we visit most Before Now
CNN 100 50
Techcrunch 900 1,700
Photo.net 2,000 1,800 (almost no change)
Problogger 3,000 12,000
JohnChow 5,000 17,000
Webpronews 7,000 9,000
Greenpeace 7,000 7,000 (no change)
Doshdosh* 7,000 33,000
Treehugger 10,000 5,000
got2begreen 100,000+ 100,000+ (no change)
*who fell drastically is doshdosh
The Universal Sites
YouTube 2 3
Google 4 2
Facebook 6 8
Wikipedia 9 7
Yahoo! remained as no. 1 (Universal position).
Congratulations Yahoo!, Google and Wikipedia 
.