“Fan conventions, where stars can take home hundreds of thousands of dollars in exchange for a few hours of time, once were the domain of has-beens and sci-fi novelties. But the business has become so lucrative — think $500,000 for Captain America’s Chris Evans or The Walking Dead favorite Norman Reedus to appear — that current TV and film stars are popping up at events like Salt Lake City Comic-Con and Heroes and Villains Fan Fest.”