When i worked in a cinema we used to tell people, "the film itself is on the screen at..." One projectionist used to marvel that people were still late, and sometimes thought that was when the ads started. I concluded that people were so used to that practice that the word "itself" was not enough on its own to make people realise what we meant. I generally added, "ads and trailers start at..." to hopefully avoid that.

I always wondered if there was any rule against this as obviously it would cut into ad viewings. The distributor occasionally sends someone round to check the cinema is reporting their tickets sold correctly (to pay them correctly) and I wondered if they ever rang up to book and check nothing like that happened!

It was a while after I stopped working there that they joined the 21st century and had online bookings at all.