Just to speak up for another county -- it doesn't happen (as much) with F/S work, but no-shows/no-calls were not an uncommon problem in my massage work -- some clients seems to feel that basic courtesy is optional in this line of work. (You know they wouldn't pull these stunts on dentists and accountants, after all.) And a bloody royal pain in the ass such men are, too...
Also, the question comes up: if you're late for kick-off, whose problem is it? On the extremely rare occasions when I am late, I make up for it. But if a client is late, and I've been sitting around waiting on him, do I still owe him a full session when he finally shows up? (Actually, the first time I probably would give it to him. But casual, chronic lateness is another story, and reflects an inherent disrespect and attitude that makes my antenna go up...)