--- title: Pareto Principle (80/20) — definition | RGM® Glossary url: https://realgrowthmatters.com/glossary/pareto-principle/ updated: 2026-06-10 source_html: https://realgrowthmatters.com/glossary/pareto-principle/ --- # Pareto Principle (80/20 Rule) Pa·re·to prin·ci·ple/pəˈɹɛtoʊ ˈpɹɪnsəpəl/noun Peas in a garden, land in Italy, revenue in your CRM — the lopsidedness is everywhere once you count. Term : Pareto Principle Alias : The 80/20 rule Named for : Vilfredo Pareto (1848-1923) Named by : Joseph Juran, 1940s-50s ## Forms & parts of speech 80/20 · shorthand The vital-few pattern. "Run the **80/20** on the account list before planning — then staff for the vital few." ## Definition in plain terms The Pareto principle observes that outcomes and causes are wildly unequal: roughly 80% of effects flow from 20% of causes. In marketing's ledgers it shows up everywhere — a slice of customers drives most revenue (and most CLV-model skew), a few products carry the catalog, a handful of keywords deliver most organic traffic, a few pieces of content earn most links. The numbers needn't sum to 100 or sit at 80/20; the LOPSIDEDNESS is the principle. ## The mechanics The pattern reflects power-law distributions natural to compounding systems. The working method is simple: rank any input list by output contribution, find the elbow, and treat the two groups differently — concentrated investment for the vital few, efficiency (or pruning) for the trivial many. The classic error is amputation: the long tail often feeds the head (small customers become big ones, tail keywords build topical authority), so 'cut the 80%' needs a feeder-check first. Recursion is the power move — 80/20 the 20% again and find the 4% driving 64%. ## When it matters Reach for it whenever effort is spread evenly across unevenly valuable things — account lists, content calendars, SKU marketing, support load. It's the intuition under customer-centricity math (Fader's skew), ABM's tiering, and content pruning. Its limit is its bluntness: it describes the CURRENT distribution, not the possible one — yesterday's tail contains tomorrow's head, which is why the principle guides resource WEIGHTING, never abandonment, without further evidence. **Worked example.** An agency serves forty clients with identical effort and burning margins. The Pareto pass ranks contribution: eight clients produce 76% of revenue and nearly all referrals; the bottom fifteen produce 9% of revenue and 60% of support tickets. The redesign tiers service deliberately — senior staff and quarterly strategy for the vital eight, productized service for the middle, price increases (which prune politely) for the bottom. A year later revenue is up with two fewer staff — the firm finally invested where the curve always said it earned. **Failure modes to watch.** Cutting the tail without checking what it feeds; treating 80/20 as exact arithmetic; running the analysis once and never re-ranking; and using the principle to excuse ignoring small customers who were becoming large. ## Synonyms & antonyms ### Synonyms Pareto principlethe 80/20 rulelaw of the vital few ### Antonyms uniform allocationpeanut-butter budgeting ## Origin & history Named by quality-management pioneer Joseph Juran (1940s-50s), who generalized economist Vilfredo Pareto's 1896 observation that about 80% of Italy's land belonged to 20% of its people into the 'vital few and trivial many' — and later admitted the principle should perhaps have been called the Juran principle, having named it modestly for its inspirer. Etymology: [source](https://en.wikipedia.org/wiki/Pareto_principle). ## Usage trends Search interest for this term over the last five years: [View interest-over-time on Google Trends →](https://trends.google.com/trends/explore?q=pareto%20principle&date=today%205-y) ## Common questions What is the Pareto principle? : The observation that roughly 80% of outcomes come from 20% of causes — a pattern of lopsidedness, not exact arithmetic. Where does the name come from? : Economist Vilfredo Pareto observed the pattern (Italian land ownership, 1896); quality pioneer Joseph Juran named the principle for him decades later. How do marketers apply it? : Rank inputs by output contribution and weight investment toward the vital few — after checking what the long tail feeds. ## Related tools & calculators - tool[CAC calculator](/tools/cac-calculator/) - tool[LTV-to-CAC ratio](/tools/ltv-to-cac-ratio-calculator/) ## Resources & people to follow - referenceJuran's Quality Handbook — the 'vital few' formulation - book*The 80/20 Principle* — Richard Koch - book*Customer Centricity* — Fader (the CLV application) Curated, non-competitor resources verified per term. ## Related training - module[Marketing analytics](/training/marketing-analytics/) ## Disciplines Areas of marketing where pareto principle (80/20 rule) is a core concern: [Measurement](/training/marketing-analytics/)[Growth strategy](/training/growth-marketing-foundations/) ## Read next ## Related terms [Customer Centricity (book)](/glossary/customer-centricity-book/)[Peter Fader](/glossary/peter-fader/)[CLV](/glossary/clv/)[Niche marketing](/glossary/niche-marketing/)[LTV](/glossary/ltv/) ## Sources 1. trends[Google Trends — "pareto principle"](https://trends.google.com/trends/explore?q=pareto%20principle&date=today%205-y)