A scam run by a fraudulent company that involves attracting customers by setting up (or just copying) a seemingly independent review website, giving the highest marks and great comments to the fraudsters, and less favorable reviews to honest competitors.
If we run a Mochahost scam, we can get away with selling more of our crap products, while making our naive competitors suffer.
That one friend in your group who you secretly hate because they are always borrowing money, food, cigarettes, etc. And never pay you back or show appreciation. They expect everything to be handed to them in life.
My friend just sits at the bar all night waiting for guys to buy her drinks, she's such a moochapotamus.