I don't disagree. But I wonder if the reason it was a ghost town when people reinstalled the app was precisely because it took a month for all the users to hear

I don't disagree. But I wonder if the reason it was a ghost town when people reinstalled the app was precisely because it took a month for all the users to hear about it via word of mouth. If they had been able to send an email blast out to all of their users at once, perhaps there would have been enough people reinstalling the app that day to kick start it back into popularity. Overall I find it a fascinating case study, just because they fell so quickly. If the founders wrote a memoir I would be very interested in reading it.