Paul Roiter's London-based startup, Dingo, is a fan-to-fan ticketing app that enables iOS users to sell unwanted tickets. Roiter says the app is designed to mitigate the risks of fraud inherent in competing secondary ticket markets such as Viagogo, Stubhub, and Seatweave, as well as classified ad sites such as Craigslist and Gumtree. “You have to trust that the counter-party is genuine and not a scammer hiding behind a fake account," Router says. "Then there is the awkward issue of payment. Sellers often want to receive the money first, putting the buyer at risk. Even if the buyer and seller decide to meet in person there is still the risk that one party doesn’t show or the tickets exchanged are fake." Scalpers are discouraged from selling tickets on Dingo since they cannot be sold for more than their original price. Roiter notes Dingo only charges a 10 percent commission, versus the 25 to 30 percent charged by competitors. The app has an escrow payment model to prevent fraud, guaranteeing buyers a full refund if they do not receive their tickets. Users log in through Facebook or Twitter and Roiter says they can list tickets in 30 seconds.