Yet another great post by Horace Dediu. Few interesting quotes before you read the whole thing.
On adding features:
A change that is ignored is not only valueless, it may actually destroy perception of value. It creates clutter and confusion. A change that is absorbable is valuable. It is meaningful.
On importance of improvement insight:
Paradoxically, the improvements are not usually things that users ask for. Surveys always show that consumers want “better battery life” or a “bigger screen” but delivering something else entirely which nevertheless leads to mass adoption shows an uncanny insight into what really matters. Indeed, those who deliver only what customers ask for end up marginalized and bereft of profit.