What is "SEO gap" and is it useful?

Maybe people who are deeper in SEO than myself have already heard about "SEO gap" and there may be people who think it is useful but...

First, I need to clarify what "SEO gap" is. You start with identifying the search leader and its market share for certain region. Good source for information is Comscore. For example let's take Google as the leading search provider in US and assume its market share is 75% (the number is close but may not be completely acurate). Then you look at your analytics data and you see that from all search engine referrals you have, those from Google are 82%. Here is the math:

SEO Gap = Referrals from Search Engine - Search Engine Market Share

For the example above:

SEO Gap = 82% - 75% = +7%

So far, so good! Now you know how to calculate a number and you even have a name for it. Now what? What does this number tell you?

My personal opinion is that calculating SEO Gap is result of "analysis paralysis" (term is trade marked by Robert Kiyosaki but I really like it:)). On the question "Why is this useful to know?" I never get satisfactory answer from our BI team, but I see this every month in our scorecard. The answer I most often get is:

• Knowing the SEO gap you know how much the traffic you get from the search engine deviates from the market share for this search engine and this is your opportunity

Normally I don't get it (stupid me:)) and ask follow-up questions. It is logical to think that being in the negative numbers is not good for your web site and my first question is: "So, we would like to be in the positive numbers - right?" The answer to this one really messes up my mind. No, you don't want to be in the positive numbers because this means that you don't get enough traffic from the non-leading search engines and you eat from their traffic (read "you lose users who use other search engines"). As it comes out the ideal number is 0% (ZERO). Zero means you get exactly enough traffic from this search engine as you are supposed to get. Period. And what? What does this tell me? Why do I need to know this? What is the action I can take when I know that? "If you are not ZERO you know that you need to go and optimize either for this search engine or other engines", is one of the answers. Yes, but I don't know which one is the engine second by market share and how do I compare to it (because you don't have it on the scorecard). And even if I know, how does this help me?... I really got distracted (even in my post). I pay too much attention to a number and I don't look anymore at my business.

Here is why. Let's assume that I receive 10M referrals from search engines in that region and Google has 75% market share. Let's assume that my site is at ZERO SEO gap, which translates to 7.5M referrals from Google. Woohoo! I am good! Sure, I am if I don't look at my competitors. They may get 30M referrals from search engines and their SEO gap may be -35%. If you do the math this translates to 30M * (75% - 35%) = 30M * 40% = 12M. Am I good? Of course not! I suck! Because I spend time calculating number that needs 1/2h to explain and many more hours to translate to the scorecard while my competitors spend time to drive traffic and maybe improve their rankings, keep people on their sites, improve content to encourage linking and who knows what else. If I can summarize with two words: my competitor "drives business", while I "invent numbers".

What I learned is that if I am in the Web business I should not spend my time inventing numbers; I should spend my time (and my BI team's time) more wisely and measure the right things, not some hypothetical "what if" scenarios. I should be practical, not theoretical - my Web site is a business for me and not a science project.

By the way, how do you feel when somebody tells you: "Your goal is to be ZERO"? Really excited - aren't you?