If the chances to contract a disease increase 10%, we would all be much more worried and depending on the disease even panic. Yet it would be more accurate to ask how much the disease is common in our population: if originally out of 100 people 1 catched the disease, the 10% increase would sound much less worrying than if 90 did.
If a company boasts a 100% increase in revenue in the past 3 years, we would feel confident in its good shape. Yet it would be better to ask how it got there year after year: if the revenue progression would be something like 100 – 150 – 250 – 200, than we might want to inquire what happened during the last year and our confidence would fade.
These are just a couple of examples of size instinct, the tendency to be impressed by a lonely number out of context.
Even though it requires more effort, we should always attempt to evalute things within their stories, to avoid being pulled back and forth by the latest trending number. This is true also when we try to tell about the latest marketing campaign, or the results of the latest customer satisfaction survey.