However, two weeks ago I took a step back and thought what if we can ship a product in 48 hours and get people to pay. The result of it was Page.REST. In reality, it still took 7 days to launch it properly, but it had 10 people paid customers after the first day in business. That was a revelation to me and gave me a different perception of the approach.
I can attest being in the market is the best way you could learn and iterate a product (no matter how simple & rough the early version looks).
PS: I blogged some of my learnings from shipping Page.REST - https://www.laktek.com/what-i-learned-from-building-pagerest...