Just took a look through the Kickstarter Stats page and looked at the numbers. A bunch of things struck very hard.
A single projects category, Film and Video, had nearly a third of all funding. $71.85 million was pledged to Film and Video projects despite its meager 39% success rate. Also, the arts control about 73% of all the funding flowing to projects, but that wasn’t very striking since 9 of the 14 categories are art-type categories.
I also found some interesting stats in the successful dollars category. Even though Dance has the highest project success rate (69%), Games has a higher successful dollars to unsuccessful dollars ratio (about 14:1) that means for every unsuccessful $1 there are $14 successful ones. It does begin to seem that Games is a better cause than Art or publishing, however this could just be down to the fact that 3 of the 2297 Games projects launched managed to raise more than $1M. If we exclude all the categories in which projects managed to raise more than $1M (and that would be 7) the best categories for your money are Dance and Theater.
The conclusion, therefore, seems to be that Kickstarter is great for the arts. If you have have an arts project in mind, there is no better place to go than Kickstarter. If you have other kinds of projects in mind, Kickstarter may not be your best choice.