Everyone tells you to build in public.
Unfortunately there aren't many good tools to do so. GitHub has a very "build in public" type of vibe, but not everyone is a coder. And even us non-coders who wish to write can't be arsed to learn some disgusting markup language and learn how the hell git works.
That's why wikis are valuable. Unfortunately the wiki space has been dominated by MediaWiki (click that link to see why this is an unfortunate thing!)
WeWrite aims to become the place where people can build in public.
Each Page has version history which allows readers to scrub through the various evolutionary phases that particular thought has been through.
Users could optionally build in private, but then they'd get fewer donations. If you build in public on WeWrite, the public might decide to fund your idea before it's even mature!