I don't know exactly what the situation around shilling on 4chan is, but there is some janny involvement.
A lot of posters on /a/ are convinced it's just one janny doing it, same situation on /g/ where they think it's a mod doing it. I know for a fact the /a/ shilling janny is real and shills webtoons while shittalking anime and Japan. I know this because during the time of Solo Leveling's first season, the shilling and spam was disgustingly obvious, and so I began to act like a schizo and pattern recognize the threads' OPs. I managed to recognize his writing style and started confronting him everywhere he went. Eventually during a confrontation, I was muted (a power exclusive to jannies) and my posts deleted, the thread had only just started so it's unlikely a janny answered a report that quickly, much less used a power that they're only supposed to use in extreme cases.
For those that don't know, Muting posters is something jannies can do, it's essentially an unofficial ban that lasts only 15 minutes, it's rare for jannies to use it as they're only usually deleting posts and calling the mods to ban people. According to IRC oldfags they even get in trouble for using it inappropriately. Given the contents of my posts (accusing OP of spamming the catalog, accusing Solo Leveling threads to be inorganic) it's more likely a janitor was trying to silence me. And you can probably find other anons with similar experiences, I a least remember seeing multiple complain about their posts being deleted just for criticizing Solo Leveling.
/v/'s condition also leads me to believe there's genuine marketing departments out there that target 4chan, but I have no proof of that, unlike with /a/.
