I wonder how much under-the-radar advertising happens here. Good karma user: meaningful context to the thread "But now I just use $product" Immediate response

I wonder how much under-the-radar advertising happens here. Good karma user: meaningful context to the thread "But now I just use $product" Immediate response: "Yeah $product is amazing - but here's something related and a different to the gist" The whole thing is an aside but it's in context and make sense in the flow. That kind of advertising is massively more effective than a google/facebrick ad.