Before or after?

So you go to the cinema - you settle down and what's the first thing you see?  Trailers for upcoming attractions.  Perhaps you've never wondered, but why are they called "trailers" when they come first? Well the cinema-going experience was not always as it is today - Prior to the multiplexes cinemas would have a programme - typically a feature film, with a shorter supporting film. and a newsreel or cartoon, or something similar. and this would be shown on a continuous loop and you could buy a ticket and go in and watch the programme from wherever it had got to until you'd had enough. Inded there were people in the cold weather who would buy a ticket at 2.00 (when the cinema opened) and then stay there in the warm right through until it closed at 10.30 or thereabouts.Anyway, the point is that the teasers for "forthcoming attractions" would be played AFTER the main feature. which is why they were called trailers, but because it was a rolling programme, depending on when you joined it, it could appear that they came at the start of the programme and somehow it came to be accepted that this was their proper place, and so it is today.