A blind network is a type of advertising network where the specific websites or apps that display the ads are not disclosed to the advertiser. This means that the advertiser has limited control over where their ads are shown, as the network uses algorithms to determine the placement. This can be beneficial for advertisers looking to reach a wider audience, but it also carries a higher risk of their ads appearing on irrelevant or low-quality websites. Blind networks are often used for programmatic advertising, where ads are bought and sold in real-time through automated systems.