I've met a lot of people who use Alexa data (e.g. Web site rankings, reach, etc.), but I've never actually met anyone that used the toolbar. It makes me a little suspicious of Alexa's claim to have 10M installed, which makes me doubt how accurate their rankings are. It's kind of a shame that more people don't use the Alexa toolbar, because the Wayback Machine is kind of cool - it lets you see screenshots of what your favorite Web sites looked like in past years (rateitall looked pretty funny - anybody remember 'one world, many minds?'), and the related links tool is also pretty helpful for finding similar sites. Unfortunately for Alexa, they just don't have that killer app like a Google search, or Yahoo messenger, that will cause people to think that they need it. Neat technology, less than compelling application.
