I believe the open casting calls are a guarantee your video will at least get looked at. After all you are on a tape with hundreds of others...they will be viewing them, even if they only watch the first 5 seconds of your video. Colleen was chosen at an open casting!!! Open castings are 2 min videos, single VHS that you make yourself can be up to 3 mins. I would kind of think regardless of how long it is...you HAVE to do something great in the first 10 secs or so before they pop out your tape or FF to the next person.