Alexa.com is one of the leading competitive intelligence services on the Internet—it’s one of the best ways to estimate the traffic of other web sites.

Unfortunately, Alexa can be fooled. Especially for lower traffic sites.

For example, DiamondLime’s current Alexa ranking is 155,112. This is about the same ranking that WhiteCanyon.com had a year ago when I started working for them (through SEBO Marketing). DiamondLime gets about 10 unique visitors a day. WhiteCanyon was getting about 1800 or so at the time.

How Was Alexa Fooled?

Alexa rankings are based off the browsing behaviors of Internet surfers who have the Alexa toolbar installed on their browser. Not everyone has this toolbar, and Internet marketers and web developers are far more likely to have it installed than the normal web surfer. The sample drawn from the population of surfers is nowhere near statistically valid.

Because certain groups of people are more likely to have the toolbar, the Alexa ranking of sites will be (strongly) skewed towards the sites that toolbar users prefer.

Since I work on and view my site rather frequently, and the people who like to visit my site are also marketers or developers, we fooled Alexa into thinking that my site is as important and frequently visited as a major e-commerce site for security products.

How Can I Keep From Getting Fooled?

I have known that a bias existed in Alexa rankings, but I had no idea that it was this strong until my own, sparsely visited site climbed into the top 200,000 ranked sites.

In conclusion, Alexa is a useful tool, but remember, its results can be strongly biased. Especially when you’re talking about sites that aren’t in the top 75-100 thousand. Don’t rely solely on Alexa rankings because an unethical person could simply get 15 friends with the Alexa toolbar to heavily visit his site. Use as many other methods as you have to check on your competitors.