[trisiak]

Pure speculation but could it be a network effect? I frequently visit websites that were shared by coworkers and friends over text communicators that they originally found on HN.

Obviously, not all people vote or comment either so that's a second multiplicative factor.

Finally, causation != correlation, which most likely is your point, e.g. things on HN already spread from somewhere else.

[iamacyborg]

There’s definitely a network effect. I had a post of mine do well on here which lead to a ton of mentions on Twitter and LinkedIn. There was probably more going on but I don’t run analytics on the site so can only make educated guesses as to where stuff was being shared.