An ad network is a technology platform that serves as a broker between a group of publishers and a group of advertisers.
Traditionally, Ad network would collect unsold ad inventory from multiple Publishers and offer this pool of Impressions to advertisers at a much lower price than a publisher’s direct sales. This kind of inventory is often referred to as non-premium, or Remnant inventory.
Today, many Ad networks offer both Remnant inventory and Premium inventory for all different types of media and channels.
