System, method, computer program and computer program product automate and optimize process of placing advertising campaigns on available inventory. When visitor loads one of publisher's web pages, system will be queried for advertisement that should be shown. System periodically analyzes performance data to determine optimal allocations. When queried, identifies advertiser campaign and advertisement to be shown. Results of that visitor encounter are logged or recorded for future analysis. Determination of campaign placements may advantageously be a two-phase process. First, campaign is efficiently tested on the inventory most likely to produce good results. The testing module dynamically adapts, adjusting the amount of testing on different channels until a sufficient determination of the creative performance on different channels can be made. The second phase is the resource allocation. Campaign performance data and contractual constraints are formulated as a network problem. Efficient methods for solving network problems are well known. These two phases may be further subdivided if necessary.