The notes app Vesper has closed down. I wasn't a user of Vesper but I did give it a try just over a year ago.

I'm never happy to see a product close down that the people behind it have invested in and love using, but there's a lesson here that many people ignore.

You need revenue.

John Gruber's analysis of what went wrong is simple and a lesson for anyone thinking that pricing a product is just a matter of slapping a price on it.

What went wrong was very simple. We never made enough money. Why we didn’t make enough money, what we should have done differently to make more money — those are complex questions (which I’ll tackle below). But what actually sunk Vesper was not complicated. Even as a relatively popular app at a relatively high price (for iOS), revenue was never high enough.

— Vesper, Adieu by John Gruber

Sad to see Vesper go, but hat tip to John for providing such a detailed breakdown of what went wrong and what the Vesper team should have done to generate revenue for the app. This is required reading for anyone getting in the apps game with an idea of their own.