It is good to tell friends about an opportunity.
Billy has an idea on how to make a lot of money.
Billy wants to capitalize on his idea.
Billy tells a few of his friends about the idea he has on how to invest.
Billy goes in on the investment completely alone, telling no one about it and succeeding.
Billy's friends join in, and they all reap the rewards of it.
Billy's friends get jealous about it, and stop talking to him.