What is your opinion of these famous self-help gurus?

What do you think of people like

Anne Wilson Schaef, Dan Neuharth, Deepak Chopra, Joel Osteen, John Gray, Laura Schlessinger, Marianne Williamson, Norman Vincent Peale, Peter Lowe, Phil McGraw, Richard Carlson, Rick Warren, Robert Fulghum, Suze Orman, Tommy Lasorda, Tony Robbins?

I read about them in a book which analyzes the self-help industry and which tries to find answers why these gurus are so successful. Most of them are not well known in Germany.