
In a diplomatic and romantic way, we all consider movies as a form of communication. Films are one of the best ways of storytelling. But being honest, now we have to consider the other elements, like marketing, numbers, box office.
This fact brings to the table the old debate of what is more important nowadays; the story or the numbers. In the old days, if the story was good, you had a great deal of the job already done. Now is not enough. In order to break some barriers we need to expand money in promotion, and big names.
Expanding part of the movie budget and casting a celebrity for an important role has its benefits. It takes people to the movie theatres and gives the movie a lot of attention by the media. But can a big name overlap a good character? Does a movie star take the audience out of the story?

There have been cases of celebrities doing impressive jobs on popular characters. Robert Downey Jr. has portrayed a wonderful Sherlock Holmes and a memorable Tony Stark. Kenneth Branagh earned the right to play a number of the immortal Shakespearian characters for years. Christian Bale owned the mask of Batman during The Dark Knight trilogy, as Heath Ledger and Jack Nicholson did with the Joker.
Everyone has an opinion about big stars being more famous than the character they depict: Nic Cage (Ghost Rider), Russell Crowe and Marlon Brando (Superman's father), Samuel L. Jackson (as Nick Fury or Mace Windu for example). How many of us dug George Clooney as Batman? Soon we´ll see The Rock playing an almighty demi-god, Hercules.

Mark Steven Johnson, director of Ben Affleck´s Daredevil and Ghost Rider said that the name of an actor should never stand over his character, but there are some times when the character needs something that only certain actors can bring, like Nicolas Cage did with Johnny Blaze in Ghost Rider.
So the secret of success may be in the balance. Casting a popular talented actor, yet not celebrity (at the time they are hired) for big roles might be the perfect idea. Chris Hemsworth, Chris Evans, Chris Pine, Daniel Craig, Martin Freeman, Elijah Wood, Ian McKellen, Viggo Mortensen...
At this moment, we all know Ben Affleck is the new Batman, and the internet is boiling with all kind of commentaries. And almost every actor and actress in Hollywood is getting into the fray for a role in the new Star Wars movies, starting with Episode VII. Production companies are doing numbers to find the perfect balance.
Everyone is speaking out lout.
Perhaps, with such a number of previous examples, the wisest move is to wait and see.