I used to be a big fan of Alexa, in fact I still am for some niches – If you’re researching 2 sites that are targetted to SEOs or users interested in Internet marketing/search engine rankings, Alexa data will be quite accurate for US, UK and India but when it comes to non-technical industries, for example shoes, handbags or perfumes – Alexa is pretty useless.
Alexa has launched its own little keyword tool, which they should expand over time. This tool lists keywords that drive traffic to a site from search engines (data is gathered from users that use Alexa Toolbar). So I went ahead and checked Wikipedia’s keywords and I wasn’t surprised to find “SEO” as the second most “traffic driving” keyword for Wikipedia. Reason for this is that a high percentage of SEOs or Internet Marketing experts around the world either have the Alexa toolbar installed (to check Alexa rankings of websites) or have a Firefox Addon that shows Alexa rank. Either way, maximum data received by Alexa is from people who have web related jobs and therefore is highly skewed.
Now this is obviously incorrect if you check Wikipedia’s stats that they openly share at http://wikistics.falsikon.de.
Alexa will continue being in my arsenal of tools, but expecting Alexa to deliver correct traffic rankings and keywords for websites that are not related to SEO, web design etc, is not something I can bank upon.