Programmatic buying and direct buying are different methods used to buy display-advertisement inventory. When display advertisement became a thing in the 1990s, advertisers bought ad space in bulk by striking deals with publishing websites. This expensive method is called direct buying. Things have changed. These days, advertisers can use software to purchase ad space with the help of data as opposed to traditional manual methods like human negotiation, manual insertion orders, etc. This method is called programmatic advertising and...