The folks behind VersionPress did a postmortem on what they learned running a crowdfunding campaign. They got less than half of their goal, but learned a lot and still managed to utilize the funding they did get. If you're looking to crowdfund a project, you should probably read this and any other case studies you can get your hands on.
In short, they're glad they did it:
However, I still think that the crowd-funding campaign was one of the best ways, if not the best way, to start the project. It was an awesome experience and it truly “kick-started” VersionPress. What more could have we hoped for?