I hope there's more to your app than "I see them type on my screen, and they see me type on their screen".
For a note to be useful to me, it has to be quick to make. For a note to be useful to another person, it has to contain enough context for them to be able to decipher it.
For example, the notebook on my desk reads "core 495 0.20%" which I know is the number and fraction of users in the core group - and I have enough context to know what those all mean. If I had to write down that context in a way other people could understand, it would no longer be quick to write, so it would no longer be a note.
Is your idea of what note-taking is different to mine?
It's like when you type out a quick email to your team linking to a competitor and giving a little context. That's essentially what a shared note looks like. The reason we believe it should live outside the inbox, is because the inbox is designed around time-sensitive content - not content that needs time to gestate or be talked about.
First, take all the main words you use to describe rocketr, and toss them out. Note, collaborate, share, etc.
Second, describe your product entirely through a use case. You talk about telling the story, so tell the story of a user using your app. The parts where Rocketr swoops in and saves the day, where no other tool exists to do so, is where your sweet spot is.
Lastly, distill that story down to a 10 second story. Again, avoid using the words you're trapped in now.
I've developed 3 different pitches for our product depending on who we're talking to. Investors, customers, and the general public (least sophisticated). The one that resonates best with all three is the one for the general public.
Best of luck, keep fighting.
I think what you need is a diagram like that with Google Docs, Wikis, Evernote, Piratepad, E-mail and your product. You know, something that answers every "so how's it different from" at the same time.
We had someone plan a wedding with it during the pilot.