If you want to run a marketing campaign online with display ads, you should look for the right ad network. An ad network is a technology platform. They act as intermediaries between the advertisers and publishers. These ad networks use central ad servers that enable advertisers to display their ads to their prospective customers. This allows the ad networks to collect data for tracking, targeting and reports on impressions. If you wish to run a display ad campaign, you have to check with the ad networks about the kind of packages they offer. Most ad networks comprise search engines, technology vendors and media companies.