Ever regret buying a ticket to a comedy show that just wasn't funny? Some day, you might not: the Teatreneu, a theater in Barcelona, Spain, has changed from charging for admission to charging by laugh. The theater has outfitted each of its seats with a front-facing iPad and PayPerLaugh, an app that uses facial recognition to detect smiles. Ever joke you smile at costs 0.30 euros (about $0.38), with a maximum charge of 24 euros per show (about $30). The theater says that ticket prices have actually gone up as a result -- monetary proof that its productions are legitimately funny. Teatreneu says its system is being copied in other venues throughout Spain, too. Would you prefer to pay by laugh? Skip through the break to the comments and let us know what you think.