Forum Moderators: bakedjake
Their accuracy has been debated here, but I think the quick answer is that for very high volume sites they may be fairly good, at least for comparison purposes. For low volume sites, they are less reliable. Overall, they may be influenced by the percentage of users who have Alexa installed, which is not necessarily random (i.e., more webmasters may use it than non-techies).
As John_Caius says, if you want, for personal or business reasons, to bump up your ratings on alexa, then get the toolbar yourself.
At best it is a comparative rather than an absolute measure
7 million downloads is a whole lot of data though - wonder what % of those (even if the userbase is bigger now) surf regularly?
Might be neat if Alexa gave out a bit more data on their users aggregate behavior - no personal details, just more statistics & charts. I love charts. :)