The method forces you to dig deeper into the product you are building than simply using user stories to define a product.
The way to increase your chances of coming up with good ideas is to follow the tested track to new product development success. New product development can be described as a five-stage process ...
"Managing the New Product Development Process: How Japanese Companies Learn and Unlearn." In The Uneasy Alliance: Managing the Productivity-Technology Dilemma, edited by R. Hayes, K. Clark, and C.