There's a really interesting pattern where you'll see one person start a thread asking "Hey, any recs for durable travel pants?" Then a second comment chimes in "No specific brands, just make sure you get ones that have qualities x, y, and z". Then a third user says "Oh my Ketl Mountain™ travel pants have those exact traits!" Taken on their own the threads look fairly legit and get a lot of engagement and upvotes from organic users (maybe after some bot upvoted to prime the pump)

Then if you dump the comments of those users and track what subreddits they've interacted on, they've had convos following the same patterns about boots in BuyItForLife, Bidets in r/Bidets, GaN USB chargers in USBCHardware, face wash in r/30PlusSkincare, headphones, etc. You can build a whole graph of shilling accounts pushing a handful of products.