Originally Posted by Lord Raiden

I think the simple solution that they should go with is one used by other sites in the same situation. If someone comes in from outside the currently available advertising areas, ie, if they come from Italy, but Last.FM is only advertising in German, then simply swap in ads from Google's Adsense. Adsense is EVERYWHERE, and thus, if they can't earn money from previously purchased ads through their normal channels, they can just fall back on Adsense where and when necessary and the rest will take care of itself.