Ad networks bring advertisers and publishers together. As such, they act as a broker between supply and demand in the advertising industry.
The main task of an ad network is to sell advertising spaces for certain advertising forms. If publishers have unused advertising spaces in their media, they can use an ad network to offer them to advertisers. Ad networks are utilized for various types of advertising – for example, there are ones dedicated to print or even TV advertising. In practice though, they are usually referred to in the context of online media. Here, common advertising spaces include:
Social media channels