I agree and at the same time believe it might not always be the case. Supposing I've become an expert on flying model airplanes, I've blogged, spoken, done dem

I agree and at the same time believe it might not always be the case. Supposing I've become an expert on flying model airplanes, I've blogged, spoken, done demos, it is my biggest hobby. I end up writing a book, of course I might reference it in the future, but I would never consider it advertising. Just a continuation of my fun and what I've ended up being able to also have an income off of. I don't think I'd feel tricked in that case. I go to this persons site for their material, they talk about their book too.