Your Desert Island Metric

Everyone knows the question: “What one [book|person|food|movie|etc] would you take with you to a deserted island?” That is to say, what one thing can’t you live without?

Most of us have a pretty narrow list. Perhaps it’s a book you’ve read over and over again. Or your favorite cousin — the one you would like as a friend even if you weren’t related. Or chocolate chip ice cream (I assume the deserted island has a freezer and electricity!).

Have you ever asked yourself that question about your metrics? What one metric in your business can’t you live without? What measurement of success must you have to run your business, so much so that you’d be catatonic if it went away? Even for businesses in the same category, there’s no one right answer all the time.

Conversion Rate? Net Revenue Per Customer?

For some businesses, it’s Conversion rate. For others, it’s Revenue. Yet others prefer a blended number like Net Revenue per Customer. How about Repeat Customer rate? And some folks cheat and come up with a conditional “well if I was selling X, it’d be this, but if I were selling Y, then it’d be that.” No matter how you slice and dice your metrics, choosing one is a heck of a choice to have to make!

Now, we all have a hard time narrowing down a favorite movie or food or book to one. Usually, we can get to two or three “essential” items and hate having to make the final cut. Fortunately, too, the vast majority of us will never actually be stranded on a deserted island, so choosing wrong or flippantly or impractically doesn’t carry a big penalty.

Logical Fallacies

But imagine if you choose wrong for your business. Now the stakes are far more real and dangerous. A “favorite” now has to justify itself and its impact on the business. It can’t hide behind “well we always look at that one” (a logical fallacy known as “appeal to tradition”) or “I went to the Conversion Conference and heard that Landing Page Optimization is the only way to improve conversion!” (a logical fallacy known as “appeal to authority”) or “ABC Widgets Inc and XYZ Widgets LLC both use this metric, and I sell widgets, so this must be the right one!” (a logical fallacy known as “I’m a lemming and can’t be bothered to think for myself”).

Your One better be, well, The One.

And the act of winnowing down, and choosing a final singular metric upon which all metrics are subservient, is a laborious, thoughtful, even painful process. Imagine a cross between “Lord of the Flies” and “Lord of the Rings”.

I challenge you to try. If you can narrow down your list to one number, it means that all your other numbers must, per force, be useful only in supporting/refining/augmenting The One. Thinking of it that way, the other metrics you choose to be in supporting roles might well change, and give you a very different view of your business. If they aren’t supporting The One, what are they doing there?

So I ask again: what one metric can’t you live without?

Opinions expressed in the article are those of the guest author and not necessarily Marketing Land.

Related Topics: Analytics | Analytics & Marketing Column | Channel: Analytics


About The Author: is one of the inventors of Persuasion Architecture and regularly combats innumeracy among marketers in his popular "Math for Marketers" series. John's 2008 best-seller, "Always Be Testing", written with business partner Bryan Eisenberg, has been the standard reference for conversion optimization through testing since its release and has been used for the basis of both academic coursework as well as corporate training.

Sign Up To Get This Newsletter Via Email:  


Other ways to share:

Read before commenting! We welcome constructive comments and allow any that meet our common sense criteria. This means being respectful and polite to others. It means providing helpful information that contributes to a story or discussion. It means leaving links only that substantially add further to a discussion. Comments using foul language, being disrespectful to others or otherwise violating what we believe are common sense standards of discussion will be deleted. You can read more about our comments policy here.
  • Nate Nordstrom

    Engagement Rate. # of people “talking about this” divided into # of “fans”. -Nate, Founder of and

  • Pat Grady



Get Our News, Everywhere!

Daily Email:

Follow Marketing Land on Twitter @marketingland Like Marketing Land on Facebook Follow Marketing Land on Google+ Subscribe to Our Feed! Join our LinkedIn Group Check out our Tumblr! See us on Pinterest


Click to watch SMX conference video

Join us at one of our SMX or MarTech events:

United States


Australia & China

Learn more about: SMX | MarTech

Free Daily Marketing News!

Marketing Day is a once-per-day newsletter update - sign up below and get the news delivered to you!