Value Proposition

A value proposition is a promise of value to be delivered and acknowledged and a belief from the customer that value will be delivered and experienced. A value proposition can apply to an entire organization, or parts thereof, or customer accounts, or products or services.

Value proposition
Wikipedia
Useful Value Proposition Examples (and How to Create a Good One)
ConversionXL
Value proposition canvas template
Peter J Thomson
Communicating the UX Value Proposition
UX Magazine
How I apply the Value Proposition Canvas to convince my clients to invest more time in customer research
UXdesign.cc