Please just (50 to 100 words)

Estoppel is a concept that bars a party from changing a position contradictory to a position it has taken in the past where someone has reasonably relied to their detriment on the original position. In Module 4, we encountered this concept in promissory estoppel, where a party can be bound by an otherwise unenforceable promise if someone else reasonably relied on that promise to their detriment. Is this fair? What incentives does this create for those making promises? For those relying on promises? Hypothesize a business scenario where you think promissory estoppel should apply to make someone perform an otherwise unenforceable promise.