Nobody, and I mean nobody likes popups anymore. Even though most are blocked, that sound means BACK OUT. Plus it's asking for active-x installs, another bad thing to offer peopke who don't really know how to use their computer in the first place.
Might I suggest using a popUnder that way they don't get it until they leave your site. That way they don't get ticked off right away and you get a chance to advertise to them at the end.
Lots of code on google for popunders. Best way is to find a site that does it already and view source, grab working code, modify to suite.