You may think that breaking into the Alexa top 1 Million might be hard. Well, it isn’t. Malware does it all the time.

If you monitor the Alexa list for any length of time, it won’t take long for the list churn to increase that number exponentially. You suddenly have A LOT more URLs that one million that your categorization system engineers are worried about, and that they need to keep categorized and updated. It’s one thing to put resources into categorizing a million URLs once, but it’s an entirely different problem when your “top” list changes by just 0.01% every single day with new never-before-seen domains.

Alexa Top 1 million experiences an average churn of 5,000 to 10,000 new, never-before-seen domain additions on a daily basis. Every day.

It turns out that the 0.01% is not just confined to the list’s lower quarter or even the lower half. Sites move on and off and change positions all over the list on a daily basis, even in the top 100,000. The top 10,000 (0.01%) isn’t immune from change either.

Some domains are one-day wonders, others come and go. We’ve found malware URLs lurking in the top 500, which is a little disconcerting, because well, they just shouldn’t be that popular!

Where do these new “movers” come from? Instant “cat video” popularity, blackhat SEO, and advertising are just a few of the drivers of the churn, but unless you’re in the business of categorizing website content you probably don’t care. And shouldn’t.

Anyone can get on the Alexa top one million list, even if it is just once. We know – we see newbies no less than 5,000 times a day on just this “top” list alone. We track and manage this, so our OEM partners don’t have to worry about, well, things like this. Need an OEM website categorization and URL reputation partner? We’re here to help.