While there are some superstars - think Angelina Jolie, Jennifer Aniston, Drew Barrymore, Cameron Diaz - who can afford to make one or two movies a year and have all the fame and fortune they'll ever need, others aren't so lucky.
Hundreds of others have to take work whenever, wherever and however they can get it.
While these second-stringer stars are millionaires in their own right, they haven't hit the same starry heights as their A-list sisters.
You may or may not know their names, but chances are you've seen a lot of their flicks. Here's to those unsung ladies who actually have to work for a living.
The clown - Anna Faris
Being a scream queen is bad enough, but you know you're really in for a tough career when you start off as a SPOOF scream queen as Faris did in the Wayans brothers' cheerfully idiotic Scary Movie series.
Faris has also managed to steal many scenes as a comedy ringer in films ranging from the arty award-winner Lost In Translation, where she channelled a spastic Cameron Diaz, to the cute rom-com Just Friends, where she channelled a psycho Britney Spears.
Her biggest success to date has been her starring role in House Bunny, a part she was born to play. But now Faris is finally getting the sort of top-tier mainstream comedy that has always eluded her. No, were not talking about last year's woeful Yogi Bear, but her brand new flick What's Your Number? It opens in theatres today.
As Ally Darling, a girl determined to settle down with one of her 20 former lovers, Faris gets none other than Captain America - Chris Evans - as her leading man!
But even with her newfound legitimacy, Faris isn't forgetting from whence she came - she'll still be providing the voice of Jeanette the Chipette in the upcoming Alvin And The Chipmunks 3.
The geek- Kristen Bell
Kristen Bell seems to be one of those girls who doesn't realise just how pretty she is.
Having built a solid fan base off her much-loved TV show Veronica Mars, Bell went on to specialise in nerd-friendly stuff such as the Star Wars geek fest Fanboys.
She was a voice actor in the video game Assassin's Creed, she did more voice work in the CGI cartoon Astro Boy, and yes, she provides the voice of the unseen Gossip Girl.
For goodness sake, Bell, let the plain-looking girls do the voice stuff!
Bell also ended up with a bunch of comedy geeks in Forgetting Sarah Marshall, Couples Retreat and When In Rome.
Upcoming projects include the whale movie Big Miracle.
The Aussie - Radha Mitchell
After building up her acting chops on the TV soap Neighbours in her native Australia, Mitchell burst on to the Hollywood scene in the Vin Diesel sleeper hit Pitch Black.
In the decade since, Mitchell has been ubiquitous yet oddly invisible.
Silent Hill was a stand-out horror flick and a big hit - there's a sequel due next year - but Mitchell got no traction out of it.
Mostly, she's done the sort of serious-minded indie films that no one but the film-makers' families give a hoot about, from Mozart And The Whale to Feast Of Love to The Waiting City.
One gets the sense that when Mitchell isn't churning out scarers - she also did Rogue and The Crazies - she likes to indulge her sense of integrity.
Look out - or not - for Mitchell in the upcoming Jack Kerouac biopic Big Sur.
The weirdo - Christina Ricci
Having been in the movie business for two decades - she was a child star with The Addams Family back in 1991 - Ricci has done tons of films without ever quite hitting her stride.
She has had her commercial successes such as Sleepy Hollow and her critical successes like Monster, but mostly she's just done a lot of weird stuff that people find...well, weird.
She had a pig nose in Penelope. She played an out-of-control nympho in Black Snake Moan. She was a gearhead who said things like "Cool beans!" in the Wachowski brothers' trippy folly Speed Racer.
Just this year Ricci appeared as a waitress in the porn comedy Bucky Larson: Born To Be A Star - one of the worst-reviewed bombs of all time.
Fortunately, it seems that Ricci's retro TV show Pan Am is working out a bit better, and she's also starring with Robert Pattinson in the upcoming Bel Ami.
The looker - Amber Heard
A bombshell who has had us drooling since her starring role in All The Boys Love Mandy Lane, Heard has done a lot of work on a films that few have seen.
Spin? Remember The Daze? The Informers? ExTerminators? The Jonses? The Stepfather?
The list continues.
Heard's biggest hit was probably Zombieland, in which she had a smallish role as one of the zombies. Drive Angry, in which she had a lead role opposite Nicolas Cage, was designed to be a cult hit, but failed to connect with its intended audience.
Most recently, Heard's supposedly star vehicle, the TV show The Playboy Club, was yanked off air just after three episodes.
Setbacks aside, her high-profile role opposite Johnny Depp in next month's The Rum Diary could finally be her ticket to big-time success.
This article was first published in The New Paper.