This post appeared earlier today on RealMoney . Click here for a free trial, and enjoy incisive commentary all day, every day.In the early '90s, there was a story in The Wall Street Journal on the prowess of one particular investment bank in complex mortgage securities. It is worth noting that the bank in question is no longer among us. But if you were around then, you probably read the piece; it was kind of a seminal article, particularly given the quote from one of the heads of this area at this firm, which went along the lines of the following: What we do, is, we look for the really dumb guy and sell him the rich bits of the structure, and then the rest just shakes out from there. When I was at Goldman, I had been asked by the firm to set up part of a new business. My boss at the time wanted to prep me -- that to do this effectively, it needed to be done the right way. He said, "Look, this is going to be a lot more complex than you think. We are asking you to thoughtfully build this part of the business, and want you to really think through a lot of the issues. This isn't about building a pile of revenues quickly, but building a sustainable revenue stream. Some people out there like to take advantage of the 'dumb guy,' and while that may be profitable in the short run, it really is no way to build a business. "You see, the dumb guy either goes broke or he gets smarter. If the guy goes broke, then you have built your business on shaky ground to start with, wholly dependant on one guy, and it isn't really a 'business.' If he doesn't go broke, then he gets smarter. And once he figures out that you have screwed him, that has serious knock-on consequences -- for you, for the firm, for the market. So rather than go for the easy money, the lazy money, build something that will endure. It isn't going to be glamorous. You will need to spend a lot of time in the weeds figuring out how to build something that will endure. You need to meet with a lot of clients and listen to what they need out of this product. Only then will you know how you should construct this thing, but that is exactly what we want you to do."