Features
A stripped down model is the starting point (no extras)
Extras added to create higher level models => differentiation
How to determine which features should be added?
Buyer surveys: (a) how do you like the product? (b) which specific features you like most, (c) which features could we add?
Company can assess each feature's value to the customer versus its cost to the company
A high value-to-cost ratio means feature should be added
Style and design
Style = appearance, no effect on (objective) performance
Design = goes deeper, to the core of the product