The reason why peopleare keeping on scamming on other people its because they choose to get instant wealth in a fastest or easiest way. They opt to fool other people for their own interest. They dont care about other people.
You should show the marketing tactics to sell books about : "how to be rich person or get wealthy". Rich guys sell the phrases or known facts to poor people and add more money to their bank account. This is legal version of the scam, but people always look for easy ways to get rich overnight.