[barlo]

I think the Reddit and guest blog post part of this are pretty well-known and even heavily advertised, even directly on Google Ads.

Try searching for 'buy reddit upvotes' and you'll get ads for services that do exactly what you're talking about.

[Cthulhu_]

Yeah I get e-mails every once in a while on a (non tech) website I run asking if we can do a guest post for money. It's a common advertising program I'm sure.