I agree with Thom 98. The great thing about short films is it isn't expected for a complete intricate complicated and complex story to be told. Mystery can often play a very dramatic role in short films and can separate a good short film from a horrible one. If you try to do too much, there's more room for error. Keeping it short in sweet, there's less room for doing something that could ruin the film and mystery is dramatic. It can leave someone discussing your film on a forum or over coffee at Starbucks to all their friends if it intrigues them to keep thinking about if after they've watched it and allowing their imagination to fill in the wholes, the mysteries, the untold parts of the film. While the SAW franchise can arguably be going downhill, I personally believe the original film was one of the best films I've ever seen. I am not a big horror fan, but SAW changed the genre and made an intellectual horror flick. It's visuals, intricate story line, and clincher at the end left people discussing the film for days after viewing it. Too bad, the later films in the franchise focused more on the visual and not the story, but I will forever be a fan nonetheless.
Don't get me wrong, I'm not saying make a 10-minute SAW, but making a short and sweet film with an intricate complicated twist at the end leaving the audience discussing the film for days or even leaving the end open can actually allow the film to become it's own publicity. If people are "discussing" the film for days, chances are they are recommending it to others in the process.