What is the system called that allows for real-time buying of ad inventory?

The system that allows for real-time buying of advertising inventory is known as Real-time Bidding (RTB). RTB is a key component of programmatic advertising, where ad impressions are bought and sold through automated platforms in the split second that a web page loads.

When a user visits a webpage, a request for an ad impression is sent to an ad exchange, and advertisers can then bid for that impression. The highest bid wins the right to display their ad, and this transaction occurs in real time, typically within milliseconds. This method allows advertisers to reach targeted audiences efficiently and allows publishers to monetize their ad space effectively.

RTB contrasts with other methods of buying ad inventory, such as direct buys or manual negotiations, which can be slower and less efficient. It also provides real-time data and insights, enabling advertisers to optimize campaigns based on performance metrics immediately after the ads run.