The headline and first paragraph are boring. They don't immediately click as newsworthy. They get thrown in the bin without another glance. So you'd better be by your phone waiting for that call. They're busy people.
More news comes up all the time.
If you're not in they might not phone again. So should you send a copy of your book with the press release. Most people do, but personally I wouldn't. I'd buck the trend. When a book comes in, and dozens do every week, it's probably given to the book writer and sits in his big pile of unread books.