I'm approached a lot by people wanting advertising of various sorts on NSC. Only this week a company was offering $300 per month to do either Interstitial pages (which are ad pages that appear between regular NSC pages you view and/or pop unders). I'd never do pop unders (or overs) but the interstitial thing was interesting I thought. In the end I decided to not pursue it though - we don't need any extra income currently and the existing ads get the intrusiveness/revenue balance right, I think.