When producers are taking a chance on an unknown script, the variables can be very difficult to calculate. This is why studios and distributors are more likely to take a risk on low-budget films, because there is the potential for lower losses and higher rewards. This is perhaps best exemplified by the film "Paranormal Activity," which was made by the filmmakers for $15,000 grossed more than $100 million domestically.
Movies based on popular franchises often get made because the studios know that there is a built-in fan base. This is why studios are willing to spend bigger budgets on this type of film. The built-in fans help assure them that an audience will come to the movie, even if it is not the best film. The comic-book movies made throughout the 21st century are a good example of this. Another example is "G.I. Joe: The Rise of Cobra," which, despite being torn apart by critics, more than doubled the initial cost of the production when all global box office and DVD sales results are assessed.
When a studio makes a sequel to a movie, it can predict to a degree the box-office returns it will receive. Sequels have become common during the summer film season; a good example of sequel success is "The Hangover Part II." Again, this movie was not received favorably by critics, however, the success of the previous film resulted in the sequel not only having the best Memorial Day opening weekend of all time, but also the highest receipts for any comedy on an opening weekend. The studio knew it could count on a strong box office and was willing to provide a bigger budget compared to the initial film.
Although relatively unknown actors command modest salaries, the Hollywood A-list regularly brings in paydays that total millions of dollars for a single film. Studios have to weigh the likely impact of a star's drawing power against the costs of hiring him. If a star is likely to bring enough attention to a movie based on name power, then the studios will be more likely to endure the cost. Small projects that filmmakers bring to studios are also more likely to be considered if a recognizable name is attached to the project, as this helps guarantee at least some degree of success.