Well, I have a different opinion on this matter. Sharing knowledge will increase your knowledge (and not decrease it) and if you share with people some easy earning methods with the intention to help people, in return, God will reward you more and you will feel yourself a happy and satisfied person'
But in this case, there is nothing like that. It's not like sharing your knowledge. I don't think anything exists that makes you unlimited money. If you find something from where you can make money and it's limited, you will take the maximum opportunity. If it's like kind of knowledge like web design or development and you can teach others, there is nothing wrong with sharing it even for free. In this case, even if you teach someone for free, your knowledge will grow. But, if they scam someone by giving them fake hope, remember that karma is coming for them.