Latency in programmatic digital advertising refers to the time it takes for ads, whether banners or videos, to appear on a given web page. Before the advent of real-time bidding (RTB), delays were generally due to the use of third-party servers to manage initial inventory. With RTB, potential delays are primarily related to the time required for auctions, which can be longer when sophisticated monetization strategies are implemented and the number of bidding sources increases.

If processes and technical infrastructure are not optimized, latency can slow down the complete loading of the page. When the page and its content are not fully loaded before the ad is displayed, latency can compromise ad visibility, as users might leave the page before the ad even appears.