Yeah but hard to enforce in a case like this. I mean, this is a relationship where both sides have equal to gain and lose by cooperating. Many model/site relationships are like this I think.
Its especially sad that the US is one of the only countries where pharmaceuticals can advertise their products and get all the hypochondriacs to go by their dangerous pills.
"Are you tired all the time? Ask your doctor about Xanthahol. Side effects include kidney disease and death."
How about...