It's so universal. Even when I ran /r/snackexchange there were beef companies trying to bribe me with steaks to astroturf a subreddit where people send boxes to each other. Probably dozens of companies over the years until I set a strict "offer a coupon code for your redditor-owned company on the sidebar" policy for anything I thought was branded content. The admins did a hostile takeover and handed it to a guy who used it once a decade prior and wanted to run his own third-party "verification website" farming personal information. /r/fifthworldproblems has a whole ecosystem of third-party offshoots because one of the mods tried to coup the subreddit to partner with Lovecraft slop brands off-site. /r/ebikes is nothing but brands stealth marketing, users stealth marketing their referral codes, and organic users asking why those shitty bikes keep breaking.