ABBA isn't just the pop band from Sweden. To marketer Jeffrey Rohrs, it stands for Always Be Building Audience. Keeping audiences engaged is the challenge for marketers in the future. It wouldn't hurt CUs to take a page from the late-night comedians, who employ "warm-up" acts to prime their TV audiences. That's how you have to think, always priming your audiences with content, says Rohrs, vice president, Marketing Insights-ExactTarget, during a Tuesday Discovery Session. Lady Gaga, for instance, conducts question-and-answer sessions with fans on Twitter, giving away some of her content--often before she's ready to come out to sell them something new.