Personally .... I believe there's no single "elevator pitch" that works for all people. Each situation is different and therefore what you "say" should of course be different and be based on the circumstances at the time.
Mike Klassen of Klassen Communications does an excellent job of explaining the point like this .....
"These days, I tend to ask questions, then tailor what I say based on what I'm hearing.
Since there are a few different ways I can help people, I found in the past that I might be spending too much time (even in a quick elevator pitch) talking about something that wasn't as relevant as it could have been had I spent more time asking questions up-front before going into the pitch.
As a rookie networker at the time, I was rushing to try to squeeze that pitch in before the window of opportunity closed and was potentially wasting.
People generally like to talk about themselves and their own situations, so it's pretty easy to get a good feel with where they're at even in a short bit of time, then address their needs more appropriately based on what they've said.
When I'm doing that, the other person is more-often-than-not very happy to extend the conversation because you're able to talk more specifically about their needs. (Back to the idea of people enjoying talking about themselves.)
So while I can sum up what I do in a sentence or two, or 30-seconds, what I'll say is different depending on the answers to the quick questions I'm throwing out."