Real-time bidding (RTB) is an online auction system that allows advertisers to bid on individual ad impressions in real-time and display ads to users that match their targeting criteria. RTB provides benefits like access to more high-quality leads by targeting specific audiences, cost efficiency through competitive bidding, and insights for optimizing campaigns. The document recommends partnering with an RTB expert to effectively leverage the platform's customization options and data to maximize spending and ad performance.