Programmatic advertising involves the automated buying and selling of digital ad space. It allows advertisers to target the right audience with the right ad at the right time at scale. Real-time bidding (RTB) is one method of programmatic advertising where ads are bought and sold via an automated auction that takes place every time an ad impression is available. While concerns remain around transparency, fraud and understanding, programmatic advertising has the potential to personalize advertising at scale by leveraging rich audience data and automating the delivery of individually tailored ads.