Mashable: Want to buy a concession at the Austin Convention Center? Just use your phone — mobile payments startup LevelUp is accepted at every kiosk during SXSWi 2013. It's an exciting time for the startup, which launched in 2011 and hit 1 million users just last week, only four months after hitting 500,000 users. We caught up with orange-adorned Seth Priebatsch at Mashable House to ask him six essential questions.
