Editor's note: Adam Cook is chief research nerd at research firm Cranium Tap. 

There are a handful of triggers that can achieve a guaranteed eye-roll from yours truly – most of which have nothing to do with marketing or research – but when I hear people talk about Boomers, Gen Xers or Millennials, that’s my involuntary response. While some marketing strategist or guru drones on about targeting one of these “generational segments,” I can almost hear June Carter and Carl Smith’s rendition of “Time’s A Wastin’” playing in the background. It’s a fitting accompaniment when you consider this song was most popular more than 60 years ago – the same bygone era this kind of targeted marketing strategy belongs in. 

Why such marketing blasphemy, you ask? Years of researching, interacting with businesses, reading and simply being able to do some basic mathematics has sobered me up on the reason this form of targeting offers little to no value.

What could possibly diminish such a tried-and-true, much discussed, much deployed, ironclad strategic approach? Five things:

First, who’s the governing body defining generations? Can’t readily name it, can you? Yeah, there isn’t any. The terms are so much a part of our day-to-day vernacular, we’ve assumed it must have been established by some respected organization. We’ve generally assumed that these generations are groups of people that fall between 15-to-20-year increments in the U.S. Not 15 or 20 years on the dot, just slightly random and arbitrarily defined ranges. It all really started with the Boomers – a surge in U.S. births following World War II. There were so many kids that infrastructure, education and economies had to quickly adapt and accommodate. These were kids being raised in an era of incredible growth following some of the country’s most challenging economies. Media, marketing and consumerism exploded and permeated their entire lifespans. 

A b...