I really liked this interview with Josh Porter where he talks mainly about good product design, and the importance of user feedback:

Good product design is the result of persistence as much as anything else. That’s why you hear companies like Airbnb and Evernote and others say that it can take years to figure out user onboarding or free trials or other sophisticated flows. It takes a lot of time to get your message right, get the user incentives right, get the interaction right, etc. It is easy to become impatient and throw out some great ideas prematurely.

And this:

The interplay between vision/intuition and data/feedback is that you need both. You need to be able to assess how you’re currently doing with data but also not let data stop you from taking risks with your product. Many teams become conservative over time as they rely more and more on data to make decisions. They ultimately become paralyzed and unable to build something really new.