Systems and methods are provided in which performance is simulated for each of a plurality of traffic allocation models during each of a plurality of historical time segments to obtain a performance metric for each time segment. Thereafter, an allocation value is calculated for each model based on the performance metrics. Once the allocation value has been established for the models, allocations are auctioned among the plurality of models during a plurality of auction rounds. These auctioned allocations are used to determine traffic allocation probabilities among the plurality of model so that traffic can be served on at least one website according to models corresponding to the determined traffic allocation probabilities. Related apparatus, systems, techniques and articles are also described.