Baffled about what to do with your worst-performing employees? Reward them with a trip to the Cannes Lions festival in the south of France this summer! That's the tongue-in-cheek message of the festival's official ad campaign, which launches Monday. Don't think of it as a reward. Think of it as an investment in creativity. After all, as the tagline points out, sending underperforming staff to Cannes as delegates is "cheaper than severance."