Just because you're paid the big bucks that doesn't mean you bring in the bucks. That's what a new study called the Bankability Index finds.

Topping the list of revenue generators is director Steven Spielberg, who pulls in $27.4 million at the box office and video rentals a year. Following close behind are Samuel L. Jackson with $24.4 million, Johnny Depp at $24.3 million and Tom Cruise at $24 million.

However, Robert Downey Junior, who is the highest paid actor with an estimated $75 million for 2013, was only ninth on the Bankability Index. In fact, the next five highest-paid actors on Forbes's list aren't even in the Top 10 of revenue generators: Channing Tatum, Hugh Jackman, Mark Wahlberg, Dwayne Johnson and Leonardo DiCaprio. Spielberg's annual salary is estimated at $150 million.