More prevalent in the financial industry, you have a lot of successful retirees who hold talks and write books what kind of tea they drank. Statistically nobody beats the market, so these people had very likely just luck.
Causation is not relation, everybody knows that. But it is damn hard to figure out what and often the people themselves are biased. I would say a big percentage of tips you get this way are totally useless, but to figure out which one of them depends on your judgement.