Wiktionary
profit center
n. a unit or department of a company that is responsible for its cost and its profit
Wikipedia
Profit center
A profit center is a part of a corporation that directly adds to its profit.
Usage examples of "profit center".
The sale of warships to minor states would be a useful profit center for a government like that of Haven, which needed massive production capacity for its own purposes.
To his mind, its greatest value was not as a potential profit center, but as a window on the mortal world.