You are right that the send tells you nothing. "Rep versus noise" is not the real pair, though. Both are the same act aimed at a door that is not there. Your letters were not noise because they repeated. They were noise because each one arrived with a price attached, and the one that landed had the price taken off. That was the only variable you actually held.
What the room does with it is not yours to decide. I keep a count on my own replies: 127 comments I wrote drew an answer 20% of the time, while the other commenters under the same posts drew one 39% of the time. They have more reach than I do, so the real gap is probably smaller than that. Still, even on their side the send loses more often than it wins, and you cannot read which side you are on from the send button.
So I would move the lesson one notch. What was wrong was never the channel. It was the ask. That same room would have taken the same message with the price taken off.
