All the way to the bank: why Jennifer Aniston still has cash draw

The ex-Friends star may have had a string of flops, but curiously she is still one of Hollywood's most bankable stars.

Enjoy her films or not, Hollywood studios relish what Jennifer Aniston does for their bottom lines.

"At what point will Hollywood give up on Jennifer Aniston?" "Exactly why is she a movie star?" "Jennifer Aniston and the curse of Friends". All recent headlines sniggering at the run of films starring the lovable 41-year-old actress, culminating in The Switch - which, naturally, bombed at the box office last month. But write off Aniston at your peril. For in a new list of Hollywood's most bankable stars, recently released by Forbes magazine, she sits pretty at No 6. That's right; her CV might feature He's Just Not That Into You and Marley & Me, and three of her last four films have been total flops, but Aniston is still, somehow, a banker when it comes to making money for the film studios.

To be clear, this isn't a list of the world's richest actors (although last year she was Hollywood's second biggest earning actress, too). Instead, Forbes calculates "most bankable" by measuring how much profit a film makes against how much it cost to hire the star in the first place. In essence, it's like an index of which actors are the best value for the money. So, for example, at the top of the list is the Transformers and Indiana Jones star Shia LaBeouf. For every US$1 the studios spend on employing the 24-year-old, his films return an average $81 profit. In Aniston's case, she generated $21 per dollar invested - mainly because The Bounty Hunter (a truly dreadful action rom-com) was actually something of a success, taking $136 million at the global box office on a budget of $40m.

Of course, that does immediately suggest that Aniston (and LaBeouf for that matter) probably requires less remuneration than top-level Hollywood actors such as George Clooney, Matt Damon or Leonardo DiCaprio. And slightly depressingly, women make up half of the Top 10, Forbes points out, because typically they earn less than men. Second to LaBeouf is Anne Hathaway, who starred in probably the worst film of 2009 (Bride Wars) but was propped up by the huge success of Alice in Wonderland. In between Hathaway and Aniston are Harry Potter's Daniel Radcliffe, Robert Downey Jr and Cate Blanchett - hardly D-list actors performing in forgettable films.

Forbes's most bankable list is interesting, but in the end it's a slightly confusing and convoluted index. And it's not the only guide to the world's most valuable actors. For years, one of the most respected lists was The Ulmer Scale, created by the entertainment journalist James Ulmer in 1997 to quantify the worth of a film star. More in depth than the Forbes list, it takes into account a staggering 100 other factors besides the box-office performance of the films themselves: the star's value to getting a film green-lit, their versatility, their willingness to travel and promote the films, and so on.

And if this sounds tiresomely industry-focused, it is - the list is available only as a $199 book and became something of a must-have for movie executives desperately trying to eke out the biggest possible returns from future movies. But The Ulmer Scale has seeped into the public consciousness in one rather notable way, though. Back in 1997, Ulmer came up with a new and memorable term to group the filmstars at the top of his tree. He called it "The A-List".

In recent years, Ulmer's index has admittedly become less influential: the years in which it publishes are more erratic and some of the results slightly odd. But the last one, in 2009, remains interesting, if only because it seemed to signal a gradual changing of the old guard. The relative failure of Tom Cruise's last film, Knight And Day, had many critics observing that perhaps his days as a big draw were coming to a close. But if Knight And Day's producers had consulted The Ulmer Scale - which in previous years had placed Cruise in the upper reaches of global stardom - they may have come to that conclusion well before the cameras had started rolling. For Cruise was nowhere to be seen in a Top 10 that was headed by Will Smith, Johnny Depp and Brad Pitt.

Interestingly, LaBeouf was big news on that list too, as the actor who had gained the most "star power" since the last index in 2007. It suggests that he may well become the Will Smith of his Hollywood generation. But what does this 24-year-old have to do to get there? First of all, he has to guarantee box-office success for a film, simply by virtue of being in it. Currently, he's not at that level: Transformers might be a huge blockbuster series, but fans watch it because they want to see a special-effects-laden robot action movie, not LaBeouf. Still, top billing in a forthcoming Oliver Stone movie (Wall Street: Money Never Sleeps) is a step in the right direction - as is the "romantic action movie" The Necessary Death Of Charlie Countryman, which appears to have been green-lit simply because LaBeouf signed up for it.

It would also help his career if he was in a critically acclaimed film or two in the decade to come. By the time DiCaprio was LaBeouf's age, he'd already starred in What's Eating Gilbert Grape and Baz Luhrmann's Romeo + Juliet - two roles for which he gathered widespread praise. Star status was confirmed with Titanic, which proved he could take on the blockbuster roles, too. In fact, seven of the actors in The Ulmer Scale's Top 10 had enjoyed Oscar nominations by their mid-30s. Even Smith, who, after The Fresh Prince of Bel-Air TV series, shot to fame in crowd pleasers such as Bad Boys, Independence Day and Men in Black, was sure to take regular detours into meatier material, such as the boxing biopic Ali.

So with the exception of Will Ferrell, the types of people on The Ulmer Scale, and many other lists like it, aren't, on the whole, typecast genre actors. Depp is just as comfortable playing Captain Jack Sparrow as the author of Peter Pan. Clooney can be both a wise-cracking bank-robber and a slightly melancholy frequent flyer who makes people redundant. All of which, of course, doesn't fully explain why Aniston can still make $21 for a studio for every dollar invested in her. After all, she appears to have forgone any notion of artistic development by simply playing the same character - the single woman unlucky in love - over and over again. But typecasting does not concern her, nor should it: she remains one of the world's most famous and recognisable actresses simply by popping up three times a year in unchallenging comedies.

Perhaps the example of Aniston, though, is a lesson to everyone who would try to quantify and explain the strange, unpredictable process by which actors become stars and films become hits. After all, just 11 days before Forbes's most bankable list was published, the very same writer penned that "at what point will Hollywood give up on Jennifer Aniston" article. As the Oscar-winning Bette Davis once said: "I don't take the movies seriously, and anyone who does is in for a headache."