There are many rules, some of them describe Bill Gerba on his site of http://www.wirespring.com/dynamic_digital_signage_and_interactive_kiosks_journal/index.html
Excerpts of "Making great digital signage content: Composing shots and scenes"
Whether you're making a five-second station ID message or a 30-minute long-form segment, sooner or later you'll have to come to grips with two challenges.
- First, most of the members of your "audience" don't consider themselves an audience at all: they're there to shop, visit, navigate, or do any of a hundred other things, but probably not to watch your out-of-home media campaign.
- Second, as a corollary to that, there are going to be a lot of people -- the vast majority, really -- who never see your piece in its entirety.
Six steps to better composition, people are still over-thinking how their pieces should work. We continue to see highly complex spots that, while produced with very high production values, demand too much viewer attention for far too long to be viable in the field.
While there's no guaranteed, 100% effective solution to this problem, we've found one approach to be extremely useful: treat the clip as a series of scenes and shots. Just as a movie director composes a film from numerous small pieces, effective digital signage content can be constructed from segments designed to catch attention and relay some information quickly -- sometimes in a mere second or two.
To maximize the chance of getting your message across to an increasingly distracted audience, try to remember that digital signs work more like posters than TV.
We recommend the following procedure when going from the idea phase to the production phase of your content creation process, which is kind of like storyboarding in reverse:
- Articulate your core idea as a series of messages that are only a few words long (no more than a sentence).
- Think of a single image or visual element that goes along with each of these core ideas. (One image per, for now. Don't worry, you can add more later!)
- Now, take each message-visual combination and mock up a quick poster.
For example, think about what a movie poster might look like for the message "Tide gets your whites whiter!" Each mini-poster should stand alone -- i.e. poster #2 shouldn't depend on content from poster #1.
If you're using a voiceover or other dialog, try to segment it into sound bites that go along with each poster instead of using a single, contiguous speech.
Assemble related "posters" together into scenes with transitions and segues that link them together, but don't make them depend on each other.
Finally, assemble the scenes into your finished spot.