I've been working on a web-app that is set to finish late November and I'm now looking for ways to demonstrate my app via a promotional trailer (preferably not a just a screencast) of some sort.
Are there any businesses that specialize in this?
I'm a freelancer in video production/editor/director. Your job needs planning a screenplay, a design, a voice, a music, and animation! The magic of cinema!
Seriously, you can't hire Hollywood for this, but you can hire talented professionals (most motion designers) which can make a very nice piece of pro-video to show to your costumers the power of your web-app, infinity times, and forever! On www.creativecow.com and other sites too, you can found many of them, with a demoreel to get you in touch with the level of the professional you are hiring. Sure this will reflect in budget (quality X investment) but the result will be much better and more personal than a preset-recording video of your screen.
While i've personally done some of this as a video guy, I don't exactly enjoy it and i'm going to tell you why to help you when picking your professional to help you out.
You know your product best - better than anyone (I would hope). You 'should' know who your audience is too. You should come to the table, with everything you intend to accomplish with the video.
You don't need to write the script, but you need to give as much insight as possible for the person that WILL. They can try and get excited and passionate about your product - but it's tough. And while they may get that way after the first phone call, it's hard to carry that excitement forward.
Provide details. Come with ideas, with a description of 'who the video is for' and even what kind of mood you feel the video should have.
Find out right away how they like to work. Do they like to write the script? Outsource that? You write it? Do they like to storyboard? No storyboard? At what steps do you have approval? Do they create music from scratch, or find some stock music?
There's a lot of people out there who can do the work - and most will do a fabulous job. You need to help them do that fabulous job by being prepared, organized and available.
And whatever you do, don't diminish the effort they'll be putting in. "It's just a simple video. I am thinking it should take you a few days" is a terrible way to start that relationship. If you're on a budget, just come right out and say so.
And also - after taking that all into account - remember you're hiring them for their expertise in this. So you need to let them do what they do best if you want to have the best video come out of it.
www.grumomedia.com is well known and does great work.
http://simplifilm.com/ i've also heard good things about.