becaz webmaster come on bid directory and maximum webmaster have alexa toolbar. so u have good raniking for your biding directory. ~jakki~
Alexa is an interesting site to look at, has some very good information, but when your only generating your results from users with toolbars it make it very unreliable.
I'm not really relying on Alexa ranking since they only get the rankings from those visitors who installs Alexa Tool. How about those other Unique visitors who doesn't have the tool?