The movie the fault in our stars was a profitable hit because

The movie, The Fault in Our Stars was a profitable hit because it was a deeply moving story. The movie is about two young people battling cancer, who fall in love. Many people can relate because most people know someone who has had cancer and so the story touched a lot of people's hearts.

Before the essay is shared with an audience, the thesis statement is a research tool for the writer.After the essay is finalized, the statement becomes a road map for the reader.
A thesis statement is normally at the end of the introductory paragraph of any paper and it comprises of concise summary of the main point of the essay.
Best answer is : research tool, roadmap