We used numbers from Box Office Mojo for worldwide box office returns and estimated production budgets.

FORBES: And The Forbes Oscar Goes To...'Silver Linings Playbook'

For the film industry, opening weekend box office returns determine whether a film is deemed to be a success or not.

CENTERFORSECURITYPOLICY: Vote early and often-- at the box office

The figures were compiled directly from independently audited box office returns, for the 52 West End theatres that are members of Solt.

BBC: NEWS | Entertainment | Record year for West End theatres

We used Box Office Mojo to look at the box office returns for 675 summer releases going back to 2006 to create our list.

FORBES: Magazine Article

Disney's hoping the box office returns do, too.

FORBES: Yar! Disney Banks On Box Office Booty

Mr. Grahame-Smith now feels he's in a precarious position: sought-after, buoyed by hype but still unproven in the metric that matters most box-office returns.

WSJ: Seth Grahame-Smith: The Master of the Mash-Up

Less than 2% of films account for 80% of box-office returns.

ECONOMIST: Schumpeter