Originally Posted by wehateporn

They wouldn't mind if they knew you'd promote them forever, but what they don't like is that one day those sites could be used to promote a competitor, so surfers who were searching for Met Art would end up going straight to a competitor. For example, a competitor could make you an huge offer for the domains. Playboy have something similar going on, but they don't mind you using the domain as long as they have control over it, they point it to your servers.