The best, better, only exercise helps you determine which of your capabilities and offerings help differentiate you, and which will be the focus of your positioning and messaging.
This exercise is important for the early stages of your company as you're verifying your product or service's market need, measuring your value, and answering the essential "What's it for?" questions. It is the base on which you will build your positioning.
After completing this exercise, nail down your positioning with the positioning vector template.