Once results come in from an advertising campaign, explanation devils rear their ugly heads. What are they? Those traps of illogical thinking that we can all fall into when we try to explain why a campaign succeeded or failed. There are many explanation devils, but here are three of the most common to watch for.
Post-Hoc Fallacy: The assumption that event A caused event B just because A came first. That telemarketing push increased our sales! Why? Well, we did the telemarketing, then our sales went up. Hello, explanation devil. Remember that correlation does not imply cause. Consider that event C (say, the weather) caused event B (increased sales). Or A and B are unrelated coincidences. Or B caused A.
Regression Fallacy: When a data point deviates far from the average, it is highly probable that the next point is going to be much closer to average. A deviate result is also likely to prompt human intervention. After 75 years of consistent business, a store has a terrible summer. They renovate the store, and voila, the next summer, business comes back. Must have been the renovations! Explanation devil. Unless there was a seismic shift in their company or industry, it is likely that business would have come back towards average without them doing a thing differently.
Confirmation Bias: We all like to be right. And we all have our pet theories. Confirmation bias affects our perception of current events and our memories of earlier events to support our theories. Direct mail is the best advertising medium! Every time it’s used, the store is filled with customers and sales go through the roof! Really? Or are you playing into your biases, only noticing your busy store after your DM hits the market to confirm your theory? Explanation devil!
Watch out for these devils when doing post-mortems on campaigns. Unless you’re doing controlled experiments, there’s no way to know for sure why one thing worked and other thing didn’t. That uncertainty is the “art” of advertising – a frustrating joy.