text:  He estimates it got Senator Obama an additional million votes. To be fair, Oprah is an outlier as well because she's so huge. Additionally, with her book recommendations, there'd never been anything like that in the history of book recommendations, at least in modern history. And it wasn't just an endorsement. It was a call to action to everybody go buy this book. What do we know about the more general state of endorsement? Let's say LeBron James is endorsing Nike. Yeah.