Every year Forbes business magazine publishes a list of the most overpaid actors in Hollywood, based on their earnings and the earnings made by the films they appeared in that year. This is useful for thinking about Marginal Revenue Product of Labour - basically are they worth it? When they do bring in more revenue that they are paid their MRPL is obviously positive so they should be employed, but comparative data like this allows for a quantitative comparison to be made. Obviously our own opinions of their films affect our decisions to watch them or not.
In Accounting terms, the calculation is basically the same as Return on Capital Employed (ROCE), so this is useful for investment decisions.