In a world where errors are a given, making the right kind of errors increases our odds of survival.
Becoming optimistic about pessimism.
If the worst possible outcome is rejection, you really haven't lost anything? In fact, I would argue you've gained some insight in an approach that didn't work or ruled out a prospect.
Sales is all about separating the sheep. You want to attract the ones who are interested and let those who'd never buy go.
Probabilities are the next best thing!
Create a pessimism contingency table!