are you sure ann? i think they mean you can't start a small agency(selling yahoo ads when they are in beta would be chaos for yahoo) i place them under both of my sites without any problems. Although both of the domains are basically the same site (one goes directly to the forums, and the other goes to the home page)
Try the T&C, it IS there I sure don't make any points by lying about it.
OKAY I found it for you.
It is 11-J in the T&C (you may not) J display all or part of the Ad Unit on any web site that is not enrolled in the Beta Program, or sublicense or syndicate the Matched Ads to any other entity or web site;
Well, until I see it in print I won't be using them. Especially the part about not showing them to foreign countries...not gonna start up until they decide to change the TOS and the T&C to include all this word of mouth telling people to blatantly break their own rules..
Better safe than sorry. My account will just have to stay on hold for awhile.