I'm sure subversive ads happen, but in my experience people are pretty straightforward about marking posts as paid.
Then, there's also a lot of small and medium sized manufacturers/artists where their whole channel is showing off their stuff. Kind of ad-like, but quality tends to be good and it doesn't feel sneaky like subtle product placement. Ex. there's a chinese factory that manufactures polycarbonate dome houses, they'll post montages of their domes, nicely decorated in beautiful locations. I think the product is cool, so I intentionally follow and consume their 'ad' content.
Then, there's also a lot of small and medium sized manufacturers/artists where their whole channel is showing off their stuff. Kind of ad-like, but quality tends to be good and it doesn't feel sneaky like subtle product placement. Ex. there's a chinese factory that manufactures polycarbonate dome houses, they'll post montages of their domes, nicely decorated in beautiful locations. I think the product is cool, so I intentionally follow and consume their 'ad' content.