We did a Kickstarter campaign last year and raised $45k, One way that Kickstarter could be improved is that it is not very marketer friendly. They don't make it easy to send traffic to your campaign and figure out the metrics. This is a big deal, because if you don't BYOB (bring your own backers), for the most part you'll fail. How are you supposed to do that if you can't figure out what is working? We spent a few thousand dollars on traffic from various sources, but it was a crap shoot.
A crowd-sourced funding site that got the maker-side marketing right would kill it, in my opinion. It needs to support pixel tracking (or something like it), affiliate programs, be integrated into your autoresponder systems (like mail chimp for example), and you should be able to tag visitors for remarketing through Adwords and such.
Another is that there are 3rd party apps that help you organize your backers, but who wants to pay extra for something that should be a given part of the package? Simply letting you download a csv of your backers report would be a big win.
Getting featured by Kickstarter is a big deal and can give you a big bump if your campaign has a general appeal. The guys that sell you banners and such for your campaign seem to be a waste of money -and we did waste money on that, much to our dismay. Targeted traffic probably worked, but good luck figuring out conversion rates. Getting written up on blogs helped us, but I wouldn't pay for that.