Public speakers speak for free. I speak for a living. You see, if I don't speak, I don't eat. That's the first hard lesson one learns when they run off to join the ranks of the self-employed. Of course there are lots of positives, but that's a subject for another article.
Professional speakers provide a valuable service.
They speak to people about stuff people should really be reading about. Contrary to popular belief, reading is good for you. It's a great way to find wisdom and feed the mind. Most people feel reading takes too long and it's a lot easier to sit and listen to someone speak. The Professional Speakers' challenge is to find and deliver the wisdom and deeper meaning people are seeking.