The ad maker can also film people all day and cherry-pick the results. Tell people you're shooting an ad, give it enough time, and you'll even have people jumping up and down for chat.js.
I go to many music festivals and often take photos while I'm there. In 2-3 hours I'm pretty much always guaranteed to produce at least 10 awesome photos of people with little effort. People who want to be photographed find you and go out of their way to do something interesting for the camera.
