I wouldn't assume it's not happening on HN too. Think of the value of a prominent HN user's, or several users', positive comments about a product - in our indus

I wouldn't assume it's not happening on HN too. Think of the value of a prominent HN user's, or several users', positive comments about a product - in our industry, that's probably worth a lot more than the same on any subreddit (or on any blog or on Facebook). If advertisers have reached out to users on those platforms, why wouldn't they reach out to users here? If I were unscrupulous and had a product that HN users buy or influence, I'd definitely try it. Being humans, we'd rather close our eyes to it unless we are compelled to face it - such things complicate every discussion and disrupt our happy community. And now you know why propaganda and advertising persist on Facebook and Reddit, and in society.