That’s what a ship is, you know. It’s not just a keel and a hull and a deck and sails, that’s what a ship needs but what a ship is … what the Black Pearl really is… is freedom._
Jack Sparrow, Pirates of the Caribbean
Profits are just what you earn minus what you spend. This is, of course, true, but only in the literal sense that Jack was talking about when he mentioned hull and sails.
From a societal standpoint, profit is also the award for taking on risks. NOT working, mind you. Unless they have something to rent out, everyone accepts they will have to work. That does not mean they are ready to take risks though.
For an individual, that’s optimal. For society, that’s dangerous. If no one wants to take the risk, things fall apart or never start.
To find buried treasure, pirates need people to man the ship, cook, work and ultimately dig the hole where X marks the spot. Those are easy to find, just pay them wages.
They also need a ship that is not currently used for trade or raiding and can therefore be used for the treasure hunt To find it, offer to pay rent.
Finally, who will volunteer to command, but also consequently hang if they get lost or if shovels dig up just dirt? To find such a person, you need to promise them profit.
**_When a client asks you to take a risk in general, they no longer want you to just do the work. Taking a risk should always cost extra.