Media playback is unsupported on your device Media caption What goes on behind the scenes?

Film studios spend millions of dollars each year campaigning to get their movies in the minds of the 6,000 or so Oscar voters, hoping to win their acclaim. But does it work?

Heard the one about the actress who paid for her own full-page adverts telling Oscar voters to consider her performance?

Or the Hollywood producer banned from the award ceremony for campaigning against a rival blockbuster?

Just two of the most high-profile attempts to influence what must be the most select group of voters on the planet, the 6,000 members of the Academy of Motion Picture Arts and Sciences.

Estimates for the total amount Hollywood spends on Oscar campaigns range from $100m right up to $500m in a single year.

It's not the kind of figure studio bosses like to talk about. But the film producer and blogger Stephen Follows has crunched anonymous data provided by some of his industry colleagues.

He puts the cost of a successful best picture campaign at around $10m with most of the cash going on advertising, media, talent costs and publicists.

Adverts

In Oscar season, studios aggressively pay for adverts in the trade press, politely reminding voters about the merits of their films and the performances of their stars.

Image caption Thousands of dollars are paid for billboard posters and adverts

The phrase "for your consideration" plastered on billboards and in print is now something of a Hollywood cliché itself.

A front page advert in the Hollywood Reporter in Oscar season is thought to cost up to $72,000 - industry magazine Variety is likely to charge a similar fee.

In 2011 the actress Melissa Leo, frustrated at a lack of mainstream press coverage, paid for her own adverts to push her performance in the film, the Fighter.

She was accused of "going rogue" by some. It worked and she took home the best supporting actress award that year.

Dirty tricks?

Then there is the murkier side of all this: a select group of Oscar consultants whose job it is to get their films into the minds of Academy members.

They are paid between $10,000 and $20,000 a movie but can easily double or triple that fee if the client gets nominated or goes on to win.

Academy members are invited to select screenings in Los Angeles, New York or London. Stars will often make a personal appearance or take part in an audience Q&A.

Image copyright EPA Image caption The Revenant, starring Leonardo DiCaprio, leads the Oscar nominations this year

"These are highly-paid, shark publicists who know the Academy members, know how to get to them and know what they like," Hollywood reporter Gayle Murphy says.

Outright bribery is banned of course but voters say they are swamped with free gifts and trinkets ahead of the official nominations.

"I've gotten books, cookbooks and just about everything short of Lincoln condoms," one anonymous voter told the Hollywood Reporter in 2013. "It's ridiculous."

Under official Academy rules revised in 2011 any direct lobbying by email or telephone is banned.

After the nominations are announced, studios are not allowed to hold screening receptions with free food or drink, a favourite tactic in the past.

Negative comments

Comments, either made directly or on social media, that attempt to "cast a negative or derogatory light" on rival movies are particularly frowned upon.

In 2010, Nicolas Chartier, one of the producers behind the film the Hurt Locker, was banned from the Oscars for sending out an email asking voters to back his movie over "a $500m film" - a clear reference to rival best picture nominee Avatar.

Image copyright David McNew Image caption A best picture Oscar can add $3m to a film's takings

The Hurt Locker was victorious that year and he did eventually get his statue a month after the ceremony itself.

But it's thought this kind of practice is far from a one-off.

It's suspected that those Oscar consultants may be partly responsible for the steady stream of negative stories which appear in the press in awards season.

Whether that's Slumdog Millionaire accused of employing badly paid child actors or Zero Dark Thirty criticised for condoning torture.

Is it all worth it? Figures put together by Edmund Helmer, a data analyst with Facebook, in 2013 suggest maybe not.

Stripping out other factors, he calculates a best picture Oscar win adds only $3m to a film's box office takings, far less than the $14.2m boost after a win at the Golden Globes.

That might be because the Oscars come at the end of the long awards season when films tend to have been on general release for some time.

A separate study in 2014 found winning an Academy award boosts the pay of an actor by $3.9m but actresses see a much smaller $500,000 rise.

The man behind the study, the academic Kevin Sweeney, says he can't explain the discrepancy for certain, but industry-wide gender bias with more starring roles for men is likely to play a part.

All this is about far more than money of course. Hollywood politics and recognition from your peers play an important part.

As Edmund Helmer himself writes, both the Golden Globe and Oscar races "are not just about selling tickets to the films that win.

"The awards bring opportunities to the winners - and the unquantifiable gratification of victory."

The Victoria Derbyshire programme is broadcast on weekdays between 09:15 and 11:00 on BBC Two and the BBC News channel.