TV commercials that feature a company's chief executive tend to outperform other ads, according to an Ace Metrix study. Still, while making a personal pitch works for charismatic bosses such as Jim Koch of Samuel Adams and John Schnatter of Papa John's, not everyone can pull it off. "CEOs who are dull, boring, or fail to positively differentiate a brand are the kiss of death in advertising," writes Ace Metrix chief Peter Daboll.