I think Clarkson did it before he was famous. It was when he worked for a car mag (Autocar?? don't really know which one) and got pis*ed off by the circus where you write a rave review of (say) Ford's latest, and in return they advertise in your mag and invite the journos to exotic locations for 'test sessions'.
Clarkson broke the mould and wrote the truth about some abominable car or other. The advertising still came in, and JC still got his invites to places nice.
SSD