Online advertising networks can be divided into three groups based on how they work with advertisers and publishers:
Vertical Networks: They represent the publications in their portfolio, with full transparency for the advertiser about where their ads will run.They typically promote high quality traffic at market prices and are heavily used by brand marketers. The economic model is generally revenue share. Vertical Networks offer ROS (Run-Of-Site) advertising across specific Channels (example: Auto or Travel) or they offer site-wide advertising options, in which case they operate in a similar fashion to Publisher Representation firms.
Blind Networks: These companies offer good pricing to direct marketers in exchange for those marketers relinquishing control over where their ads will run, though some networks offer a "site opt out" method. The network usually runs campaigns as RON or Run-Of-Network. Blind networks achieve their low pricing through large bulk buys of typically remnant inventory combined with conversion optimization and ad targeting technology.
Targeted Networks: Sometimes called “next generation” or “2.0” ad networks, these focus on specific targeting technologies such as behavioral or contextual, that have been built into an Ad server. Targeted networks specialize in using consumer clickstream data to enhance the value of the inventory they purchase.further specialized targeted networks include social graph technologies which attempt to enhance the value of inventory using connections in social networks.