The following appeared in an ad for a book titled How to Write a Screenplay for a Movie.
Writers who want to succeed should try to write film screenplays rather than books, since the average film tends to make greater profits than does even a best-selling book. It is true that some books are also made into films. However, our nations film producers are more likely to produce movies based on original screenplays than to produce films based on books, because in recent years the films that have sold the most tickets have usually been based on original screenplays.
Discuss how well reasoned... etc.
This advertisement for How to Write a Screenplay... concludes that a writer is more likely to be successful by writing original screenplays than by writing books. The ads reasoning is based on two claims: the average film tends to be more profitable than even best-selling books, and film producers are more likely to make movies based on original screenplays than on books because in recent years the films that have sold the most tickets have usually been based on original screenplays. I find the ad unconvincing, on three grounds.
First, the mere fact that ticket sales in recent years for screenplay-based movies have exceeded those for book-based movies is insufficient evidence to conclude that writing screenplays now provides greater financial opportunity for writers. Ticket-sale statistics from only a few recent years are not necessarily a good indicator of future trends. It is possible that fees paid by movie studios for screenplays might decrease in the future relative to those for book rights. Moreover, the argument is based on number of ticket sales, not on movie-studio profits or writers fees. It is possible that studio profits and writer fees have actually been greater recently for book-based movies than for those based on original screenplays.