I don’t know how successful the new web application upstartly will be, but I like their message:

Want to be 100% sure about your startup idea?

Get at least 5 people to put down cold hard cash for it

There’s nothing like someone giving you cold hard cash for your product or service. People will tell you, until you’re tired of hearing it, how great your business idea is, but until someone gives you some of their money for your product or service you have no way of knowing whether or not your business is viable.