No. No, no, no. The answer to "what's the single most important thing" cannot be plural.
You're asking for a lot of information to go into this ad/mailer/e-mail/etc.
What's the most important message?
All of them.
Why? The other thing I hear at least once a week is "nobody reads the copy" (yeah, thanks for that validation of my career choice). We have very, very little time to get people's attention—we have to hook 'em right from the start.
Same thing when we promote improv shows, theaters, workshops, etc. We rely on free-to-cheap marketing tools—Facebook invites, show posters, e-mails, press releases, etc.—but that doesn't mean the rules for big-money marketing don't apply. In any marketing tool, you get one main message, and everything else is there to support that one message.
That message might be:
- Your troupe name, if you're talking to people who want to know specifically when your next show is.
- Improv comedy show/festival/event, or some version of that, if you're talking to a general audience of people who want to see comedy.
- Something that makes you sound good, like a review blurb ("Brilliantly funny!"), kudos ("Best Comedy Group 2010") or a super-short description of what you do ("improvised musical").
- The famous person (or even the well-known-to-the-target-audience person) in the show.
- The other specific thing that makes this show cool, if it's not one of those four things. It might be that you're family friendly or supporting a cause or playing in a certain location for one night only. But it is the thing that makes this show worth seeing.
Here's what doesn't work:
- Confusing names of things—shows, formats, etc.—that don't make immediate sense to the audience.
- Information-free witty or catchy phrases or taglines that don't provide a reason to come see the show (besides, of course, our extreme cleverness/adorableness/quirkiness/geekiness).
- Complex messages that require them to think too hard or make a decision more complicated than "that's interesting."
- Layers of show names, producer names, troupe names and taglines.