I'm at a South by Southwest session sponsored by sister pub Fast Company, listening to Biz Stone talk about his new opinion-sharing app called Super.

Stone is the co-founder of Twitter and has an interesting entrepreneurial story about how his previous app, called Jelly, failed (some would say miserably) to get traction. I profiled Jelly once in Inc. Magazine back in the day (sorry, the link is long lost), when Stone was hyping the app as a crowd-sourced search engine.

Super is "going for fun," he says, "because if you build something fun it is more likely people will use it. If enough people use it, it can do something serious."

He explained how fun translates into useful eventually. "You have to start with fun because people have to develop the muscle memory...when they do it all the time, then they will post about when a plane lands in the Hudson. If you want to build a platform capable of toppling a despotic regime, it also has to support fart jokes. It has to do what people want."

Stone says in the early days of Twitter, they had a ton of fun. Everyone not only liked the app and believed in it, they used it constantly. I get what he is saying. Fun is the same as compelling. Fun is the same as useful. Fun is the same as groundbreaking.

Jelly didn't really catch on because, even though the marketing and branding had a fun (almost goofy) appeal, the actual product was a bit too utilitarian. It goes against what many people say about building up a brand by making it useful. Stone might be right: fun trumps useful at first, because no one really understands what is useful. The draw of apps like Twitter and even Facebook is that, initially, they were really fun.

This matches with another theme from SxSW. Earlier today, I met with a company called Spredfast and heard about this idea of a "success fail"--which is essentially a way to keep momentum, energy and fun going at high-speed and failing at least while you are attempting something great. It comes from Rod Favaron, who is the President and CEO at Spredfast. He says many companies start to get bigger and then slow down and focus on business process and get stuck. They don't keep pushing.

Stone says Jelly was a "noble idea and had the promise of the connected society. People didn't want to ask questions, but they did want to provide answers. When we launched we had a million registrations in the first few hours. We tried to get people to ask more questions but they just weren't doing it. I had a gut instinct this is not going to be the thing."

Stone says he wanted to make a dent in the world with hundreds of millions of users. He used the "bright spot theory" which says there is always something that is good no matter how dark. He found that people do like the answers on Jelly but do not post questions. He came up with the idea of Start after realizing how much people like to answer questions. To give you an idea of how the app works, you essentially post an opinion as though it was a Twitter post integrated into a picture of Bill Murray.

Super is a dramatic "success fail" in the sense that Stone quickly realized Jelly had failed but noticed how people want to give answers instead. What does that mean for the rest of us? It's more than failing big, or learning a lesson. It's literally taking failure and making it a success. It's destroying the notion that failure means blockage. These lessons seem to require a bold stance. You grab onto the failure like a bull that you will ride to success. And, you suddenly make an emotional investment in the failure and the new venture.

"If you are emotionally invested--you love what you're doing and it brings you joy and you just can't wait to get to go to work, you will use whatever it is you are building, and when everyone is saying how stupid it is will roll off your back," says Stone. "You have this indefatigable drive when you are emotionally invested."

What "success fail" is driving you? Can you relate to what happened with Jelly and how it gave birth to a new app? Note that Start is way too new to really tell if it will be a hit. But to Stone, it already seems like a hit. He talked about it like it is a new best friend. Maybe that's the ultimate win for him. He plans to use (and love) his own app.