A Plain English Guide to Real Time Bidding Since its inception in 2009, real-time bidding (RTB) has become one of the most popular ways to purchase ad inventory online. But even for experienced marketers, this type of programmatic advertising can be a very confusing concept. I, for one, get intimidated just by reading the word "programmatic." So let's break down what RTB is, how it works, and the pros and cons of using it – all while keeping it jargon-free. What is real-time bidding? Real-time bidding (RTB) is a type of programmatic advertising which involves buying and selling ad impressions in an auction-style bid. And this transaction all happens in the time it takes a webpage or mobile app to load.