Top Online Horizontal Ad Networks

A list of online horizontal ad networks. Horizontal ad networks serve direct response advertisers and focus on expanding the reach of the advertising as wide as possible. Horizontal ad networks, however, do not allow for advertisers to control where their ads end up, or who the people are that are seeing the ads. So they are often ineffective unless they advertise products with a broad base of appeal. They differ mainly from vertical ad networks, which are focused on specific topic categories - or verticals - exclusively. This can be more useful for advertising niche products. (For example, a person selling surfboards would not want to advertise to just anyone, but would purposefully seek out surfing enthusiasts.)