The fact that this particular batch of envelopes reaped no responses doesn’t mean that a future one won’t. Nor does it change the fact that a previous one did.
The lack of ROI for these particular envelopes did, however, come with a cost, one that was neither foreseen or anticipated. In hindsight, at this particular point in history, it should have been obvious that the potential concequences might turn out to be a bit of a catastrophy and given that, perhaps there never should have been envelopes. Let alone ones that made it all the way to the mailbox.
But that was a long time ago. Looong time. From now on—to envelopes.