The 80/20 rule in sales: test it on your client list first

The 80/20 rule is the idea that a small share of causes produce most of the results. In sales, people apply it to three things: a few clients bring in most of your revenue, a few activities lead to most of your deals, and a few reps close most of the team's business.

It's also called the Pareto principle, after the Italian economist Vilfredo Pareto, who showed how unevenly wealth and income were spread. Investopedia's explainer says he introduced it in 1906, and repeats the popular story that 20% of the pea pods in his garden gave 80% of the peas. Joseph Juran later took the idea into quality control, as "the vital few and the trivial many", and it spread into business from there.

The dates depend on who you read. Britannica puts Pareto's law of income distribution in his Cours d'economie politique of 1896 to 1897, and the Juran Institute says he made his observation in 1895. Investopedia dates Juran's work to the 1940s, while his own institute says the early 1950s, and adds that Juran later swapped "trivial many" for "useful many". None of that changes how you use it.

Investopedia adds two warnings. The rule is a precept, not a mathematical law, so your split can come out 70/30 or 90/10, and the two numbers don't have to add up to 100, because they count different things. And deciding to focus on the few doesn't mean the rest don't matter. So is it still true in sales? Often, yes. In plenty of sales businesses a few clients pay most of the bill. The exact split, and the reasons behind it, change from one business to the next.

The split also nests. If it held at every level, the top fifth of your top fifth, four clients in every hundred, would bring in four fifths of four fifths of your revenue: nearly two thirds. That's the arithmetic, not a promise, so treat the rule as a prompt to check your own numbers, not as a fact about your business.

Clients are the obvious place to look, and the least useful one to stop at. Each of these can be ranked the same way, and each answer leads to a different decision:

You won't know which row matters most for you until you rank your own numbers.

You need last year's revenue by client. Your CRM, your invoicing tool or a spreadsheet will do.

1. List every client who paid you in the last 12 months, with what they paid.
2. Sort from biggest to smallest.
3. Add up a running total down the list.
4. Find the point where the running total passes most of your revenue, and count how many clients sit above it.

Then look at the top group. What do they have in common? Same industry, same size, same way they found you, same person who sold to them? That pattern is worth more than the split itself, because it tells you who to look for next. The ideal customer profile entry covers how to write it down.

Your client list looks back. Your pipeline is where the rule earns its keep this month, because you can still change what happens to it.

Take every open deal and multiply its value by your honest chance of closing it. Base the chance on how often deals at that stage have closed for you before. Sort the list by that number. A handful of deals near the top usually carry most of what the pipeline is worth, and they deserve the call prep, the proposal time and the follow-up on the day you promised. The deals at the bottom still get a next step, just a quicker one.

Two warnings. A big deal with no next step booked isn't a top deal yet, however much it's worth. And a deal that's been near the top for three months without moving is telling you something. The sales pipeline management guide covers how to keep those stalled deals from clogging the weekly review.

The last test is about your time. Look at the deals you signed in the last six months and ask where each one started: a referral, a cold call, an event, a website enquiry, an old client coming back. Then look at where your hours went.

A few questions find the lopsided parts of a week fast:

• Which tasks came right before most of your signed deals?
• Which clients take the most admin for the least revenue?
• Which hours of the day get most of your replies?
• Which few people send you most of your referrals?

Tom shouldn't stop cold calling on the strength of that. Cold calls still led to five deals, and they're the one source he can turn up on a slow week. But he should move a couple of hours from cold calling to referral asks and check the result in a month. To run this test you need your activities logged, and the sales activity metrics guide lists which ones.

Once you know your split, four moves follow:

• Protect the top clients. Put their reviews in the calendar first, and make sure a person looks after them. They're also your best source of referrals.
• Drop or batch low-value work. If small one-off clients take a lot of admin, give them a simpler process, or handle them in one block a week.
• Look for more clients like the top group. Use the pattern you found, not just the size of their spend.
• Put more hours into the activities that lead to deals, and fewer into the ones that just fill the day.

Two things not to do. Don't ignore the middle of your list. Some of today's mid-sized clients will be next year's top ten if they're looked after. And don't stop finding new prospects. Every client in your top group was a new prospect once.

Managers often apply the rule to reps: a few top performers close most of the business. Check it on your own team before you act on it. The trap is what comes next.

SalesScreen argues that treating the rule as a management plan is outdated. When managers give most of their coaching, recognition and attention to the top few, the middle of the team gets less help, and the gap the rule described gets wider.

The middle of the team is usually where coaching moves the total most. A top rep who's already at their best has less room to grow than a steady rep who's one habit away from a much better month. Spend your 1:1 time where it can change the number, and use a win rate calculator to see which reps convert well but don't have enough at the top of the pipeline.

Commission is the other place the rule turns up. A flat rate pays the same on a rep's first deal of the quarter as on the one that takes them past target. If you want the extra deals to pay more, the plan has to say so, with a higher rate above target or a bonus at it. Look at what your plan rewards before you decide the bottom of the team isn't trying. The sales incentive ideas post has options that aren't cash.

• One big client isn't a strategy. If your top client leaves, a revenue split that looked efficient becomes a problem. If one client is a large slice of your year, find more like them before you need to.
• Last year's top clients aren't next year's. A split from one year can reflect one lucky deal, so check two years if you have them.
• A big client who takes a huge amount of your time can be worth less than their revenue suggests, because revenue isn't profit.
• A deal that "came from a referral" often needed three follow-up calls and a meeting as well. Crediting only the first touch undervalues the rest of the work.
• New reps and new markets won't fit. There's no history yet to rank, so the rule tells you nothing until there is.

• Investopedia, The 80-20 rule (aka Pareto principle): Pareto in 1906, the pea pod story, Joseph Juran in the 1940s, the rule as a precept and not a law, read 26 October 2026
• Encyclopaedia Britannica, Vilfredo Pareto: his law of income distribution in the Cours d'economie politique, 1896 to 1897, read 26 October 2026
• Juran Institute, Pareto principle (80/20 rule) and Pareto analysis guide: Pareto in 1895, Juran in the early 1950s, the vital few and useful many, read 26 October 2026
• SalesScreen, The 80/20 rule in sales is outdated and what to do instead: the argument against using the rule as a management plan, read 26 October 2026