IMO, this is no longer the case. Basically any new thread is getting astroturfed by marketing teams, and it seems like Reddit started doing SEO to promote newer threads, so the days of reliable reddit reviews seem to be over
Subreddits that are about buying things (/r/buyitforlife, /r/frugalmalefashion) are done. Same with any askreddit thread that's like "What's a product for under $x that changed your life" or something like that.
I still find /r/cooking gives good recommendations, despite the fact that the world of recipes is filled with spam and low quality content. Maybe the unit economics of astroturfing just don't work out for it.
Definitely true. Marketing teams at multiple roles paid third parties to advertise on Reddit. Even tongue in cheek comments about incidents are marketing.
