Hollywood agents, marketing executives, financiers and other industry experts now stress that filmmakers and actors have no choice but to get involved from start to finish in a project, especially when it comes to marketing.

In today’s film industry, an actor who won’t pump a movie,  won’t get as much work.

Studios have always used stars to promote films, but in the age of social media, the methods of promotion have diversified, increasing the demands on many actors.

A decade ago, stars like Al Pacino or Kurt Russell often resisted showing up at a theater for a movie opening – let alone tweeting their whereabouts.

That star attitude is now outdated, as studios look for any way to build a dedicated audience. It has become  increasingly important to set a film up with a community that wants to own it in order to maximize the success potential of the project.

The myth is that a movie happens so fast you can start building your audience later.  The fact is, to compete in today’s market where the consumer has so many choices , you need to start marketing  and finding ownership of an audience at  both casting and script green lighting.

Here’s just one example of this process.

For the movie “21 Jump Street,” Sony staged a contest on Twitter between stars Channing Tatum and Jonah Hill to gain the most followers over a set period of time. The winner would release the trailer on Facebook.