Abstract: Various embodiments enable demand driven allocation of advertisement insertion opportunities, e.g., avails, that are associated with television content or other media entertainment from a provider. In at least some embodiments, projections for an inventory of avails from a provider are obtained using an iterative projection model. Auctions are conducted using the projected inventory to allocate the avails to advertisers using bids from the advertisers. Offers to purchase avails from the providers can be formed based on these auctions and submitted to the provider on behalf of the advertisers. Based on a response from the provider to these offers, yield analysis can be performed to update the projection model to reflect results of the submitted offers. Projections for subsequent iterations can then make use of the updated projection model.