What if you see the ad, and decide to check the movie out, and it's terrible - a waste of your time and money? What if you see a slick ad for a restaurant, and it turns out the restaurant spends more money on ads than on being a good restaurant, and it is a waste of money? Are you better off?
Which is why it is ridiculous to approach the situation from a "what if..." perspective. We should approach it from net expected benefit, else everyone gets to pretend they are the one true purveyor of good and classy ads.
