Alexa Fallacy - As if Anyone Thought Otherwise
Okay, no more theories, no more guesswork, I finally have proof that Alexa data does not jive with actual real internet traffic patterns. Well, at minimum it doesn’t match what they claim it matches - it does prove other interesting facts, but I’ll get to that in a minute. My Alexa rating is pretty high. Ha.ckers.org does tend to get quite a bit of traffic (somewhere around 11k-14k unique users a day visit the site). Most of my traffic is comprised of the security industry, but I do have quite a few SEO readers - especially the blackhat SEO crowd. That comes from a long standing bridge between web application security and SEO and it also happens to be that I’m one of the few security people who talks about both. For whatever reason I have a lot of webmasters who aren’t particularly interested in security who read my blog as a result of that bridge.
One thing that most SEO people (and indeed webmasters in general) have in common is that they happen to all have Alexa (or here for Firefox users) installed on their browser. It could easily be seen a spyware because it does report on where you are visiting but it also gives you the relative page rank of the page for your troubles. This can easily help you assess if a site is new, or if it’s old, if it’s got a real following of people, or not, etc… It can also tell you if the domain gets traffic to other cnames (if that’s interesting).
But there’s been a long standing theory that Alexa data does not actually indicate true ranking. Finally I was able to prove it (at least to myself - maybe other people proved it to themselves before now, but I haven’t seen any hard and fast stats until today). So here’s what the current graph of my Alexa ranking is over the last several months:
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You’ll notice the two biggest spikes on July 30th and January 16th (just a few days ago). So you would naturally assume those are huge spikes in traffic, right? Well let’s look at the significant events of those two days in particular. On July 30th 2006, the site was Slashdotted. To most people that’s probably a pretty significant event and you’d expect to see a huge jump in traffic. Let’s look at what it really did:
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You can plainly see very little traffic change for the 30th. Sure it was up a great deal for the average weekend, but it was really not much of a spike, and nothing like the traffic levels you’d expect for the 4,000th biggest website on the planet, right? Could it be that SEOs also tend to read Slashdot? Okay, that’s really just a theory, so let’s put it aside for now. Now let’s look at the events of just a few days ago (the 16th).
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You can see that I did get a fair amount of traffic but it was nowhere near my highest day this month and I certainly didn’t jump up by more than a few percent of my normal traffic load (the 17th proved to be a much higher traffic day and the 8th was the day the firewall died on us). Where did all the Alexa traffic come from that made next to no increase in the number of users we get in a day? Well as you will remember, just a few days ago a self proclaimed Whithat SEO said he intended to hack a bunch of sites. Ha.ckers.org was named in that list of sites (despite the fact that I really do not consider ha.ckers.org to be an SEO website). Ha.ckers.org was linked to by his website, and many other SEO’s picked up the list as well. In essence, every SEO that would possibly click on a link to a site named “ha.ckers.org” did click - and all in one day. Thus you can see only a minor increase in traffic on the 16th but a huge spike in Alexa ranking.
Quod erat demonstrandum.
It is interesting to note how many SEOs use the Alexa toolbar. I bet that database would give away a lot of SEO secrets if it were ever compromised. Spyware never sounded so good.
January 18th, 2007 at 10:29 am
“Finally I was able to prove it (at least to myself - maybe other people proved it to themselves before now, but I haven’t seen any hard and fast stats until today).”
Actually I did some experimentation with alexa rankings myself about 11 months ago. It is VERY easy to boost an alexa rank by utilizing the a9 search engine and their redirection script. I performed a series of queries that would bring my site up, then followed them which called their redirection script. Alexa uses a9 and the toolbar to gather traffic stats, so all one would need to do is query the same web apps that the toolbar uses. I performed some tests and managed to see decent traffic spikes (I rotated a few proxies each hitting the different urls used by alexa).
Bottom line, alexa ranks are easily faked and could be used to ‘justify’ to a person buying a domain name that you are selling that it gets decent traffic. As an academic excercise I’ve created a tool called ‘RankMe’ which visits all of the proxy websites, tests the proxies, sorts through the good ones, then uses these to query sites including alexa and netcraft (and yes it works).
- zeno
http://www.cgisecurity.com/
PS: I tested the alexa trick on another one of my domain names, not the site listed above
January 18th, 2007 at 10:51 am
I’d like to point out that I’ve never once messed with my traffic. This is a lab, but for the most part I try to see what “normal” traffic looks like for a site of this size. I do zero blackhat SEO tricks on this domain, whatsoever, however, I do monitor the site like a hawk.
January 18th, 2007 at 10:58 am
Same for my core domain as well. Don’t want to affect it in any negative way, get it banned, etc… This is what ‘test’ domains are for
- zeno
http://www.cgisecurity.com/
January 18th, 2007 at 11:33 am
I can only confirm that Alexa Numers are worth nothing.
Lately i manually compared the traffic on the site from a friend with mine and alexa did not see that my traffic is 3 times more than my friends site. Not only in pageinpresions, but also in unique visitors.
January 18th, 2007 at 11:55 am
I was just amazed when I moved up 4,000,000 places in a couple of weeks. All it took was a couple of people with the browser toolbar coming back to see if it got any higher. No-traffic website with lots of Alexa-juice.
Barely sub-300,000 is about right for me.
January 18th, 2007 at 12:49 pm
So perhaps what we are proving with Alexa ranking is how important it is to the SEO industry.
January 18th, 2007 at 5:10 pm
From a lurker:
January 19th, 2007 at 7:36 am
although it’s right that alexa rankings are quite inaccurate and - more important - “adjustable”…. it’s still true, that alexa gives you a quite good glimbse on the traffic levels ob BIG sites and the growth of the industry as a whole.
you can easily push the rank of your blog to something X0.000 by simply using 3-5 alexa clients a day. but you wouldn’t be able to push the WSJ beyond the NYT…
so you shouldn’t rely on alexa stats, BUT you can use that as one of a few indications combined with signs like delico-bookmarks, netratings-figures, etc…
January 19th, 2007 at 1:44 pm
Sorry late comment but just wanted to add: http://www.mattcutts.com/blog/thoughts-on-alexa-data/
January 19th, 2007 at 4:15 pm
That Matt Cutts feels Alexa is worth quoting is a little scary. That means either Google is using it as part of their super secret pagerank heuristics or they personally use it (either way - scary). Thanks for the link, Mike. I read his blog for a while but stopped reading his blog after he submitting that weird post about Yahoo stealing content from Google after Google was caught red-handed stealing Yahoo’s content.
February 23rd, 2007 at 9:18 pm
I write code, some tracks ip, page views, etc. Externally, other code tracks the site elsewhere. On occasion, Alexa is used to get some crude idea of how the site compares. Given a large margin of error, Alexa is a ballpark and that’s all it is. If one were really doing a comparative analysis, well a toolbar would just not do. I imagine carnivore (govt spyware at the switch) would do a far better, albeit illegal, job.
June 13th, 2007 at 3:45 am
Totally agree with mr.deeds . If anyone still thinks alexa data is reliable or conclusive, fair enough.
But hey, tis only means an advantage for those who distrust, so why bother?
Lizzi