A Yahoo study released today claims that online display advertising increased the number of relevant searches by more than 61 percent, reports DM News. The study was based on an analysis of a campaign by Yahoo client HarrisDirect. Clicks on sponsored search links leading directly to the client's site also jumped - 249 percent - after a user was exposed to a display ad campaign, Yahoo said. The study found that consumers exposed to the campaign clicked on 139 percent more links to the HarrisDirect site, through both paid and organic listings. Yahoo used a test group and control group. The test group was exposed to the ad campaign, whereas the control group was not.