>Because the tiny niche audience isn't a cost effective marketing group? A

That's the magic of Reddit, 4Chan and every other cesspool where any niche is only a slight URL change away from any other niche.

It's trivially easy to add niche subs 2, 3 and 4 to the list of places that you target.

Yeah and then any mod with half a brain sees you're spamming things everywhere and bans you.

1) That's a whack-a-mole exercise when the astrorufer buys accounts in bulk.

2) You can tune these systems to be indistinguishable from a flesh and blood product fanboy at first glance. Not all spammers drop the same comments mentioning their product everywhere. You can dilute it with meaningless AI generated banter so the mod has to scroll through a couple pages and connect the dots before deciding whether you're a bot or just an idiot who happens to like some product.

Except that there is a culture of looking for and outing shills in a lot of subs, and since you can see someone's entire post history it's usually not hard to confirm or at least provide solid evidence for it once you suspect it. I had someone out an astroturfer who posted a banal non-response to one of my comments just the other day.