I've never been a big fan of social media measures, but other people like them. "That's the best we have," people tell me.

Alexa, for example, is a longtime favorite for people to gage traffic, despite its obvious and admitted shortcomings. Some bloggers have even taken to using it as a valuation in order to determine ad rates. Maybe not any longer. Alexa changed its algorithm and plenty of people are cheering and weeping. Me, I'm just laughing because I had doubts (and still do) over its validity as a measure anyway.

Why? Well, for reasons like the impact of Entrecard (see exploring-rank-entrecards-impact-on.html here for one thing. And my April Fools Day satire revealing-secrets-strategy.html here for another. But most of all, my favorite reason is because Alexa always told me that it is not a valid measure.

"Alexa's data comes from a large sample of several million Alexa Toolbar users and other traffic data sources; however, the size of the Web and concentration of users on the most popular sites make it difficult to accurately determine the ranking of sites with fewer than 1,000 monthly visitors. Generally, traffic rankings of 100,000 and above should be regarded as not reliable." — Alexa

In other words, sites with traffic less than 1,000 per day or in top 100,000 (which leaves an amazingly thin, maybe zero, middle) are not accurate. Of course, that doesn't mean Alexa doesn't have uses. It does.

But it also means that Alexa rankings are nothing to crow about or lord over others, especially when the difference of being on top or near the bottom can change with the simple switch of an algorithm. This morning, that switch was flipped and, very suddenly, combined ranking systems across the Web, including the AdAge 150, have been turned on their heads.

Tomorrow, I would not be surprised to see people attempt invalidate it; mostly those who embraced it when they were at the top.