One or more data centers are selected to host an online conference. The selection of the data center is based on a set of metrics that are measured from ‘synthetic’ transactions. These synthetic transactions are sent between candidate data centers and the participants in the conference call in order to measure one or more performance metrics (e.g., link quality metrics such as delay, packet loss, etc.) These measured performance metrics are used to determine a centroid that represents the geometric center or ‘center of mass,’ of the link quality between participants and data centers. This ‘link quality centroid’ is used to select a subset of data centers as candidate data centers. The candidate data center with the best average performance metric(s) is selected as the data center to host the conference.