Advertising Network

An online advertising network or ad network is a company that connects advertisers to web sites that want to host advertisements. The key function of an ad network is aggregation of ad space supply from publishers and matching it with advertiser demand. The words "ad network" by itself is media neutral in the sense that there can be a "Television Ad Network" or a "Print Ad Network", but is increasingly used to mean "online ad network" as the effect of aggregation of publisher ad space and sale to advertisers is most commonly seen in the online space. Ad networks are primarily involved in selling space for online ads to appear. This online advertising inventory comes in many different forms, including space on websites, in RSS feeds, on blogs, in instant messaging applications, in adware, in e-mails, and on other sources. The dominant form of inventory remains to be third-party websites, who work with advertising networks for either a fee or a share of the ad revenues.

An advertiser can buy a run of network package, or a run of category package within the network. The advertising network serves advertisements from its ad server, which responds to a site once a page is called. A snippet of code is called from the ad server that represents the advertising banner. Smaller publishers often sell their entire inventory through ad networks. One type of ad network, known as a blind network, is such that advertisers place ads, but do not know the exact places where their ads are being placed.

There are two types of advertising networks: first-tier and second-tier networks. First-tier advertising networks have a large number of their own advertisers and publishers, they have high quality traffic, and they serve ads and traffic to second-tier networks. Examples of first-tier networks include the major search engines. Second-tier advertising networks may have some of their own advertisers and publishers, but their main source of revenue comes from syndicating ads from other advertising networks.