The Pareto Principle states that for many events about 80% of the effects/results come from 20% of the causes/effort.
In all my life I found the Pareto Principle to be true most of the time and my one lighthouse principle. It prevents me from optimizing for edge cases where it’s not necessary; it allows me to say no to 80% of the stuff which doesn’t move the needle; it frees me from pushing for perfection when good enough is all that is needed.
Sometimes I find people misinterpreting the Pareto Principle though — they put in 1% of the effort and expect to get close to 80% of the result. Which is far from the truth — you typically end up with a pile of crap.
The whole Lean Startup movement’s obsession with MVPs (Minimum Viable Product) seems to exaggerate that notion (note though that it’s about building a Minimum Viable Product — and viability often requires 20% effort, not 1%).
There is no reward without work. The Pareto Principle is not a cop out for not skipping the work — it’s all about being smart.