Entertainment marketing has typically relied on the 'spray and pray' model of marketing and advertising in the past. The studio makes a big movie, they allocate a ton of money for P&A (prints and advertising) and then they sit back and pray they make their numbers on opening day.
Those days are gone. Long gone. The business of blockbusters is so huge - with literally billions of dollars on the line - that eliminating risk and ensuring success is a full-time job everyone, including the marketing teams.