So I've been here a little longer than you, and the most I've ever gotten is in the mid-3K range. My posts generally land in the 1k-2k range (with some not even hitting that level). And looking at daily posts in general, it seems that's the case for a lot of good posts. I think it may be better to look at the initial post as an aberration -- the right time, perfect subject matter, the right people reading it, etc -- than as what should be expected, and as you note, that may very well have raised your expectations.

If I were to not make another sat this month on SN (including dropping off the MSM leaderboards), I'd still have made more stacking here than from everything else I've done, combined, other than trading fiat for sats. And based on the way sats stack, most of my posts have a lot of people who like them. So if I've hit my "limit," that's fine, both from an income point of view, and also an ego one.

While I think all three of your points are legit, one more (that's an offshoot of MSM) is that different time periods will lead to different zapping patterns. I'm sure someone's done some stats on zapping during bull or bear runs, or other external factors that might impact numbers.

And I'm also guessing that there's probably at least some impact from other hot posts, either in the form of essentially being the sat magnet/sink for a lot of folks, or possible being the rising tide that lifts other ones, depending on how things work out.