A good product is not a bucket of features, a mere bulleted list of
things users can do. A good product is an exercise in exclusion. A
good product is defined as much by what it doesn’t do as by what it
does. This is especially true at the start. At the onset, people don’t
care about you, they don’t know what you do, and they certainly won’t
put up with a confused product. This apathy must be acknowledged and
combated in a product that does one thing extremely well; otherwise it
won’t stick.
(Via Hacker News)