A lot of Hollywood actors advertise in foreign countries, and even do voice-overs ( like the Demestos ads ).
I imagine the Clooney ads you mention aren't shown in the United States.
George Clooney is one of my favourite actors - not only he is good at being an actor,but there is nothing prima-donnish about him or pretentious. I don't think he is strapped for cash,just perhaps he doesn't think it to be below himself to appear in ads.
Incidently,Max his Pot Bellied Vietnamese Pig has died,so he is in mourning.
Ta Ta
Marky B