Last night I caught part of Big Idea with Donny Deutsch on cable. Donny was interviewing billionaire Mark Cuban, who is one of the smartest entrepreneurs I've ever followed. The best written article I've seen about how Mark turned Broadcast.com into a multi-billion dollar company is the chapter in Net Entrepreneurs Only, published around 2000, to highlight a dozen or so successful online entrepreneurs. The work ethic that Mark and his partner Todd had back then is nicely described there. Mark talked about it again last night. He described a typical work day.