eWeek writes that Yahoo Search Marketing (formerly Overture) is getting ready to display pay-per-click banner ads, joining competitor Google in expanding the role of search advertising. A Yahoo spokeswoman confirmed that in the next few weeks Yahoo plans to start testing banners that are displayed based on relevance to a Web page's content. The test will run on Yahoo's network of sites, not on partner sites, she said. The ads will be dynamic, initially appearing as a banner ad and then transforming into a sponsored link. She provided no further details.