The idea is that by the time you scroll to the bottom of the page, you should have a pretty clear idea about the product and how it's useful to you.
Email replies? Email replies to what?
How does it integrate with Gmail?
It's probably better to present this as a story.
It's three things: * A cross platform desktop app * Gmail plugin * iPhone app
If you create a task for someone not using the system, it'll send them an email instead. Any replies to that email will get turned into comments in Taskforce.
I think you're right about representing it as a story, perhaps a life cycle of a particular task.
But when I first read through I too was confused about the comparison to 37signals and their new draft app.