Mark Cuban is a clueless publicity whore. But he does have a lot of marketing ability because of his fame. There is a pervasive misconception that if somebody is wealthy, then whatever they say is right, regardless of their domain expertise. You can tell by some of the questions he asks that he has no clue what he is talking about. Put him in a room of PE analysts and he'd get eaten alive.

But the reality is that most people who go on the show need sales, and having Mark Cuban willing to advertise for you on Twitter and such is very valuable for a growing business. His "expertise" is of little to no value. I certainly agree with you there.