This (excluding errors of judgment on the part of one of the parties). One party values money (or data, etc) more than the time/materials/end products and the

This (excluding errors of judgment on the part of one of the parties). One party values money (or data, etc) more than the time/materials/end products and the other party values those end products more than the cash (or privacy, etc): the trade happens. Both parties are ahead of where they started. This doesn't mean you're always happy with the terms, but it does mean that you're coming out ahead on the deal. If you are willing to do a deal where you know you the other party is coming out ahead and you're not: you're just an idiot.