The Silverman Uncertainty Principle:
You can’t measure your word-of-mouth campaign with a conventional control group design, because the purpose of word of mouth is to set off a chain reaction of second-order word of mouth that reaches everyone quickly. In experimental design, it is called “contaminating the control group.” You can’t use a pre/post design because you can’t control for the other variables without a control group, which you can’t use. Also, the second order effects are much more powerful than the initial exposures. Your boss is going to hit the roof over this.
The Problem with Word-of-mouth Measurement
Word of mouth is the only marketing method that can’t be measured accurately. Even more disturbing is that the more effective the program, the more likely any attempted measurement is going to be invalid. That’s a serious problem, because most companies now require that you show a substantial return on investment (ROI) for any marketing method you use.
Don’t get me wrong. You can plot the number of mentions of your product on the social media when compared to your competition, but that’s not the same as measuring the bottom-line effectiveness of a particular word-of-mouth campaign. That campaign isn’t the only thing that’s happening in the world. You can’t use a control-group design, for instance, to measure the purchases of people who attended your Webinar. The major effects may be on friends of friends. In most cases, that can’t be tracked back to its source.
This lack of measurability goes contrary to common sense. Everything else is measurable, so it seems obvious that word of mouth must be measurable.
More to come on this, but I welcome your comments.