The question by Washington Post's Erik Wemple (I just read a pile of books by cable talk-show hosts — so you don’t have to) wasn't exactly top of mind. His exploration of the subject is worth a look, however. The best answer: sales and synergy.
“It’s a huge deal,” literary agent Howard Yoon notes via e-mail when asked about the promotional head start of the cable news hosts. “They’re all big bestselling authors . . . because readers see their faces on TV every night.”