I expected so, so very much more of you.
They bog down my system, they annoy the crud out of me. Not to mention they cheapen your site in ways I can't even begin to express. Only the worst of the worst sites I visit use on pop-unders any longer. Seriously, only the really low-rent operations allow pop-unders.
Even the FOOD NETWORK site, one of the worst sites on the web, ditched them, fercryin'outlloud.