It can broadly be categorized and disinformation architecture.
If myself and someone else on this forum had a financial interest in Seachem, we could go around and tell people that Seachem PhoGuard makes African cichlids more colorful. Do that on a couple of forums and Facebook, and guess what? Tons of people are suddenly buying Seachem PhoGuard.
True, people don't understand placebo, their African cichlids would grow and get a color and the will praise PhoGuard and start marketing and defending for you. Saying results speak for themselves.