1. Useful for those who cannot (or are too lazy to) code - instant setup.
2. Cut out the middle man and save on the 5% (or $X) fee. Then again, you will still be paying a bit for the service.
Thoughts?
[1] Transparency which means you are responsible for the project and the provider has no legal obligation whatsoever.
AFAIK is has been the alternative solution for people who had very horrible experiences with Paypal's 2 month+ waiting period for transaction procession approvals or with paid scripts like Agriya SF where one has to pay no less than $1000 just to make subtle changes in code or wait for a month to get a response on their forum.
Then there is http://ignitiondeck.com/id/ and http://appstorm.com.br/wordpress-crowdfunding-template/ and http://siteorigin.com/wordpress-crowd-funding/ for wordpress
One company I know chose Agriya recently, as it's fairly easy to find programmers.. as it seems to be popular in this segment.. and money wasn't constraint for them as they planned to get big cut from campaign creators.