I think webmasters have widely viewed the Alexa rankings as meaningless for a long time now. The rankings are very easy to "game" and the the toolbar usage among the general public is minimal.
I was reading a post at one of my favorite Search Engine forums today that really illustrated how minimal that use is. The post was not about Alexa but the reference was made as a comment on tracking traffic.
The writer has a site that generates tons of traffic from a group that would be representative of the general population and out of 600,000 visitors just 60 were using the Alexa Toolbar (which is where the Alexa rankings come from)
So, if you have clients that are worried because someone told them they had a poor Alexa rank - pass that tidbit along to them

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