The 80/20 rule is dead.

There's an old principle, dating back to the 1890s, called Pareto's Principle¹, or more commonly the 80/20 rule: 80% of sales come from 20% of your customers. Vilfredo Pareto noticed the pattern first in his own garden, oddly enough, 20% of his pea pods produced 80% of his harvest, then found the same ratio in Italian wealth distribution. The name stuck decades later when management consultant Joseph Juran generalized it, and it's been showing up in business advice ever since: protect your top tier above everything else, because that's where your revenue actually lives.

It's intuitive. A lot of businesses build their whole strategy around it.

In 2010, Byron Sharp, Professor of Marketing Science at the University of South Australia, published How Brands Grow (totally worth the read btw), which stared the 80/20 assumption in the eyes and used real purchase data instead of a hundred-year-old thought experiment to really test it. The specific number was further disputed in a 2019 paper he wrote with Jenni Romaniuk and Charles Graham: and it's not actually 80/20. It's much much closer to 60/20. 60% of sales come from your top 20% of customers, not 80%. 

That twenty-point gap matters. 

If 40% of your revenue is coming from customers outside your top tier, and every offer and every ounce of attention goes to your loyal core, you're ignoring almost half your business.

There's a reason for the gap, and honestly, it lands hardest on a business your size. It connects to something called the Double Jeopardy Law, first identified by social scientist William McPhee in 1963 and developed into a full model of buying behavior by Andrew Ehrenberg, a German statistician and renowned consumer researcher who ran the.

It's since been validated across categories as different as retail banking, insurance, luxury goods, and grocery stores: a smaller customer base doesn't just mean fewer customers, it means those customers also buy from you a little less often, on average, than a bigger competitor's customers buy from them.

A 30-member yoga studio isn't just smaller than a chain with fifty locations. Its members also show up a little less regularly than the chain's do. That's not a loyalty problem you can fix by working harder on the customers you already have. 

Growth comes from adding more customers, including the light, occasional ones, not from squeezing more out of the same small group.

Your best customers deserve real attention, don't get me wrong. They just aren't the whole story, and treating them like they are quietly caps how much you can grow.

Here's the gut check: pull your last year of promotions, loyalty perks, referral pushes, whatever you spend marketing effort on, and sort them into two piles. How much went to people who already buy from you, and how much went to people who don't yet? If almost everything lands in the first pile, you're spending your effort protecting a base that was never going anywhere, while the group with real room to grow gets nothing.

None of that changes anything on its own. It only matters once it changes where you actually put your attention next.

If you want to see this play out with a real, concrete example, I walked through it in a piece on discount codes specifically, why they're one of the easiest places this mistake hides, and what to check instead.

Reach me at alyssa@warpandweft.studio or book time using the form below if you want a second set of eyes on your own numbers.