Abstract: A computer-implemented method for matching a display advertisement to a user within a large-scale, non-destructive user modeling and experimentation environment using real-time traffic. The method commences by populating a user profile object (containing demographics, history, and behaviors of the user) for use during concurrent operation of a production platform and an experimentation platform. To implement non-destructive testing, the method continues by cloning a portion of the real-time traffic for use by the experimentation platform while concurrently delivering the real-time traffic to the production platform. The production platform and the experimentation platform operate concurrently, scoring matches between the user profile objects and a plurality of display advertisements for selecting among the best-scored advertisements.