This is open to interpretation. I would say a customer who comes along asking for something you don't already have may present itself as an opportunity. If, in

This is open to interpretation. I would say a customer who comes along asking for something you don't already have may present itself as an opportunity. If, in fact, you're already planning to do X and X is the thing the potential customer is asking for and you charge him double what it would have cost you to build it anyways (and it was in your list of "features" all along), then why wouldn't you? It ends being "free" money and you land a new satisfied customer. While I agree with the article, there are, as always seems to be the case, many exceptions.