Conventional internet routing is handled using routing protocols such as the Border Gateway Protocol (BGP). However, simple BGP does not account for latency, packet loss, or cost. To address this problem, smart routing systems that route traffic fast and in a cost-effective manner are implemented. In one approach, smart routing systems measure, compare, and analyze round-trip latencies and other metrics between a customer premises and one or more endpoints. Optimal inbound and outbound transit providers are selected for each endpoint based on these measurements. Other smart routing systems collect and analyze Real User Monitoring (RUM) data to predict latency performance of different content origins for serving data to a particular client based on the client's IP address and the content origins' IP addresses, which are ranked by performance. These rankings are used to steer traffic along lower latency paths by resolving Domain Name System (DNS) queries based on the performance associated with the IP addresses.