Can you trust Alexa’s numbers?

It is very important to understand that there is no way for external metrics tools such as Alexa, Compete, Ranking, Netcraft, etc. to provide accurate data.

Their information is collected from their respective toolbar usage. Alexa has the broadest distribution than others, but there are still a lot of people that don’t use those toolbars or browser plugins.

Their data is particularly useful if you are in a technical field: search and affiliate marketing, web development, etc. A large portion of your potential visitors probably have one or more of these toolbars installed.

A while ago, there was an interesting project regarding the efficacy those metrics:

Conclusion – The Value of External Metrics

This survey represents only a tiny sampling of sites in a niche sector, albeit a relatively popular one in the blogosphere and webdev/tech space. Based on the evidence we’ve gathered here, it’s safe to say that no external metric, traffic prediction service or ranking system available on the web today provides any accuracy when compared with real numbers. Incidentally, I did log in to Hitwise to check their estimations and although I can’t publish them (as Hitwise is a paid service and doing so would the violate terms of service), I can say that the numbers issued from the competitive intelligence tool were no better than Alexa’s in predicting relative popularity or traffic estimation.

The sad conclusion is that right now, no publicly available competitive analysis tool (that we’re aware of) offers real value. Let’s hope withing the next few years, better data will be made available.

What is the problem?

In statistics, when you need a sample that represents the entire population that you are measuring, data is collected carefully and completely to avoid any bias. Unfortunately, there is no way to configure the toolbars of sites or people grouped in similar samplings. Users install them at will and the ones installing them are usually advanced users (Not your typical gardener).

Why use the data then?

In my case, the content on my blog is highly technical, so there is a high probability that most users have the Alexa toolbar or the browser plugin.

For comparative purposes. By comparing my blog’s Alexa to a blog directed at a similar audience (seobythesea.com) I was able to tell if I am in the right path.

Should you use it?

How technical is your audience is the right question to ask yourself. If you target casual readers, it might not be very useful.

Competitive research or privacy attack?

I found an interesting tool via Seobook.com. It exploits a “feature” of current browsers that do not properly partition persistent client-side state information (visited links and caching information) on a per site basis.

The tool can identify URLs in your visitor’s browsing history. Aaron suggests this be used to check if your visitors come from competing sites and adjust your marketing strategy accordingly.

This might not work as Aaron might expect. You can only tell that the visitor visited those URLs in the last n days (n the number of days the user keeps in his or her browsing history). You won’t be able to tell when, how often or how recently those URLs where visited.

While this is very useful for marketing purposes, the window for taking advantage of this for other purposes is huge. Collecting information on users without their consent doesn’t sound very good either.

Reader Dave comments:

I’ve always been conscious of the technical possibility of this and taken some safeguards against it. Still, as a user, I’d be furious if I knew this technique were being used on me, and I will be keeping my eye out for any precedent-setting legal challenges to this.

As a publisher/affiliate, I refuse to stoop this low. It’s disappointing but not unexpected that a great deal of readers here would be so sanguine about something so blatantly unethical.

Your user’s history object is none of your [edited] business.

Imagine a phisher that uses this to identify the on-line bank you use. With this information, his scam will be far more effective. Most people ignore emails from institutions they are not affiliated with.

Another reader pointed to a Firefox plug-in that solves the visited-link based attack problem. Here is another plug-in that prevents cache-based attacks. I installed both of them immediately.

The tool Aaron mentions exploits the visited-link vulnerability. Here is how it works:

Your browser, by default, colors visited links in a different color than normal ones. That information is available via CSS and client-side Javascript. The script works by pulling a list of target URLs, using Ajax (this happens with no user action), inspecting their color and flagging the ones that have the visited-link color — these are the ones the visitor has previously visited.

    if (link.currentStyle) {

    		var color = link.currentStyle.color;

    		if (color == '#ff0000') /* Here is the color inspection */

    			return true;

    		return false;

    }

This is possible because our browsers don’t make sure the links flagged as visited are not in a page in the same domain of the link. It is very likely this will be fixed in future browser releases.

It might seem that disabling Javascript solves the problem, but this trick can be done as well with CSS only. Check https://www.indiana.edu/~phishing/browser-recon

Another form of attack, not used by the tool, is measuring the time the browser takes to open target URLs. URLs that have been visited are generally cached and load faster. Comparing timing information one can tell if a page was visited or not.

The plug-ins mentioned above protect from both types of attacks.

For more information visit: http://crypto.stanford.edu/sameorigin/

See also this papers for more background information:

Protecting browser state from web privacy attacks
Invasive browser sniffing and counter measures
Timing attacks on web privacy

Your competitor is your best friend

As I mentioned earlier, for me success is about what, how, and work.  This is my simple formula.

Anywhere my customers or potential customers express their problems and frustrations is a place for me to dig out opportunities.  Forums, blogs, mailing lists, news groups, etc…   Your what should be driven by your customers’ needs.

Most critical for success is how we do it.  What sets us apart?  What is our UVP?  This is where following your best competitors closely, pays off.

Nobody is perfect.  There is always a better way to do things or at least to appeal to another audience.

My approach is not to simply copy what my competitors are doing.  This is the easiest path, but it is very difficult to stand out by just being another XYZ.

I prefer to look at my competitor’s solutions as their prescribed answer to customers’ specific problems.  The key here is that what needs solving is the customer’s problem, and there is rarely a single solution.  My solution is how I would solve it better leveraging my strengths.

Assessing competitive levels

Critical to success is competing where we know we can excel.  This might sound obvious, but many entrepreneurs fail to identify exploitable opportunities.  Don’t get me wrong; I love competing.  There is no problem with dreaming big.  Even if we want to go after Dell or Microsoft, we have to find a really smart plan to achieve that.

Realistically it is wise to start very small and have a clear and smart plan to grow bigger.

I do this with SEO.  I always target niche keywords first — keywords that no other SEO or few others are targeting.  When I conquer those keywords, I move on to the more competitive ones.  This has the added benefit that my relevance profile looks natural to the search engines.

Here is a tip I use to find such keywords.

Google and other search engines let you search for words in the title, url, body, and the text in the links pointing to the web pages.  You can use this information to assess whether there are savvy SEOs targeting that keyword niche.

It’s been well known for a while to SEOs that the link text in the links pointing to a page carry enormous weight.  You can practically rank first page for keywords that are not in the body text if you use the link text effectively.  Many websites that rank high do not contain those keywords in their incoming anchor text.

How competitive a keyword is, is usually measured by the number of sites listed for the keyword search.  For example, a search for “seo” in Google returns 125 million results. Very competitive!

Searching for “allinanchor:seo” returns under 3 million results.  A lot of results but far fewer than the normal search.  A search for “allintitle:seo” returns under 5 million results.

To assess how competitive a search phrase is, I prefer to compare different searches: intitle, inanchor, intext, and inurl.  This cues me as to what extent websites are being actively optimized.  This is my real competition!