Prioritizing the right features to build in your product is one of the most important parts of product management. Some features create more customer value than others.

But can picking the wrong features actually make your product less valuable to your customers? Odds are that most features are negative value features.

Features can have a negative value to users: they make the products more difficult to understand and use. We are finding that people like products that just work. It turns out that designs that just work are harder to produce than designs that assemble long lists of features.
-- Douglas Crockford, JavaScript: The Good Parts

It's not only the obvious negative value features: ones that are annoying, redundant, or broken for users, but also good-willed ones that work and solve a real problem – just not your customers'. The mismatch between perceived and actual customer value shows up in pricing and marketing – products priced too high and segmentation pitfalls to name a few.

Keep Your API Surface Small with any sort of product, technical or not. Experiment on willingness-to-pay.