Millennial Media is the leading independent audience platform in digital advertising. The company collects roughly 3-4 terabytes of log data per day from their ad servers. This data is used primarily as an input to the optimization systems for their mobile ad campaigns, where they can place ads for clients and evaluate the effectiveness of those campaigns by analyzing media and site performance as well as consumer behaviors. Millennial Media evaluated multiple Hadoop distributions and selected MapR. A key and differentiating feature of MapR was the multi-tenancy capability, which allowed them to physically segregate the data and the workloads—to move the data and workloads into specific subsets of the cluster so they could run production jobs in separate nodes of the cluster from the other workloads.