50-60% of Web users have popup blockers, but popups still make 6% of the ad market

According to Nielsen/NetRatings, pop-up and pop-under advertising comprised 6% of the total online ad impressions in September 2004, the same as it did in October of 2003. An ad network Dedicated LA says that on average 50-60% of Web users are now actively using pop-up blockers.