Abstract: A method is provided for dynamically controlling the pace of online impression delivery among multiple geographic regions in a real-time bidding (RTB) system. Target geographic locations associated with a campaign are identified, and target geographic regions associated with each target geographic location are identified. A pacing score is determined for each target geographic region. The bidding system makes bidding decisions regarding RTB bid requests received from an RTB exchange based at least on whether the respective bid request is associated with a target geographic region, and if so, the pacing score for that target geographic region. A campaign-related impression is delivered for each winning bid, and impression delivery data is stored for each target geographic region. The bidding system automatically adjusts the pacing score for each target geographic region based on the stored impression delivery data for that geographic region, and uses the adjusted pacing scores for subsequent bidding decisions.