Television confers credentials through impression. It automatically makes you an expert. Successful television interviewees engage and interact with their audience. Someone who has enjoyed watching you on television will eagerly expect to enjoy reading your book. Television perpetuates perception.
Dialogue is better than monologue.
Audiences vicariously become part of a conversation. They turn off lectures. Interviews can have different tones. Questions may be presented differently, but you will be answering the same questions.