How do mainstream films target and maximise their audience ?

Mainstream films use a variety of ways to target and maximise their audience. First of all, mainstream films use well known or highly rated actors or celebrities or they look similar to the famous person to appeal to audiences as they may be a fan of them increasing the chance of them watching the film. Straight Outta Compton uses actors who look very similar to Dr. Dre, Eazy-E and for Ice Cube they use his son O'Shea Jackson Jr. as he looks very similar to Ice Cube. Even though this mainstream film doesn't use the actual celebrities themselves, it's better to use actors who are younger and similar as the film looked at the past of N.W.A and the film would feel weird if they were the same age as they are today, making the film look more real and engaging maximising their audience. Mostly, all mainstream films release a trailer before the official release of their film to hook audiences and get them interested for the film, however if the trailer is bad, most people will assume that the film will be bad but Straight Outta Compton had a very successful trailer.