If you seek to please 90% of your potential customers, all you need to do is the usual thing.
To please half the remaining potential market, you're going to need to work at least twice as hard.
And to please the next half, twice as hard again. It's Zeno's paradox, an endless road to getting to the end.
So, a letter with a stamp gets you on time deliverability 90% of the time.
Priority mail gets you the next 5%, and if you want to be sure of reaching just about everyone in a trackable, reliable way, you're going to have to step up and pay for a courier service. (And note the expensive part… you often don't know which people need to be couriered, so you have to pay to do it for everyone).
The rules apply to more than fulfillment. They apply to bedside manner, to customer service, to effort and originality in the kitchen as well.
Cheap food, quickly served, will please 90% of the audience. You'll have to invest in quality, preparation and service to get the next half, and then double it again for the half after that… etc.
Health care works the same way. 90% of the patients will respond to a treatment, but the next 5% will cost twice as much, and on and on…
The very end of the curve, the .5%, might be unpleasable, uncurable, unreachable without insane effort. Which is why organizations that please everyone are so extraordinarily rare.
One approach, which some organizations use, is to redefine your usual systems so you are able to please most people without your team going through a Herculean sprint every day, and then (this is a key element as well), eagerly and regularly apologizing and giving refunds to the one in 150 where it just can't be done.
Perfect is nice, but you can't afford it. None of us can.