"some big sale hinged on, that subsequently no one has used" Yes, but who cares if they used the feature or not (!?!) the question was, did the buyer think it

"some big sale hinged on, that subsequently no one has used" Yes, but who cares if they used the feature or not (!?!) the question was, did the buyer think it was 'essential' for the deal to go through. I mean, cynically of course, but it matters.