You know, every time I run across this poster, the more I become convinced that it's one of the best posters on this damned site. I hope it made it into one of them poster books. Simple, memorable, fitting, well-done.
If one chose to look at the humour in this poster, you could say it's kind of funny that he's jumped before the plane has hit the building. Then it's just a poster of the classic image of failed stock market guys jumping after the market crash, which has been cartoonist fodder for a couple of decades.