Despite strong growth in the number of companies paying to advertise on the Internet, a significant number of firms fill their Web site ad space with banner ads promoting their own products and services, according to a report released today.
AdRelevance, a division of Media Metrix Inc., said that house advertising--ads placed by Web publishers on their own sites--accounts for about 20% of all available online ad inventory. The Internet advertising measurement firm said it monitored house advertising on the 500 highest-trafficked ad-supported sites between January and April.
