In theory, I agree with this -- in practice, I suspect you have to do a bit of subjective triage, particularly once you get past a certain volume level (which i

In theory, I agree with this -- in practice, I suspect you have to do a bit of subjective triage, particularly once you get past a certain volume level (which is itself subjective). The key is "upset by specific features/aspects." Bob writes to you, "Hey, I really like this app, but feature X is very important to me." Sam writes to you and says, "Your app is a useless piece of shit." Writing back to Bob to say, "Thanks for your feedback, I'll consider that for the next version" -- or even to say, "Thanks for your feedback, but I'm sorry to say that feature X isn't on our roadmap" -- may well be worth your time. (Especially since your time, in this case, is probably about two minutes, less if you set up a couple Text Expander snippets for this.) But is writing back to Sam worth your time? It may be that Sam feels the same way that Bob does, that he mostly likes your app but considers feature X a critical omission. But you have to get him to stop flinging flaming poop at you and actually explain what his dilemma is. And he may just hate your app, full stop. He may be too inarticulate to explain what he needs from your app. He may just like flinging flaming poop.