1. A method for executing marketing campaigns, the method executed by a computer system and comprising: receiving, via a computer interface, information for a marketing campaign associated with a supplier of items characterized by fixed capacity and deferred consumption, the information for the marketing campaign including a promotion for an item of the supplier and execution criteria for executing the marketing campaign to present the promotion via a computer network site; receiving, via the computer interface, forecast data for the supplier, the forecast data computed based on future availability of one or more items provided by the supplier; and automatically modifying the execution criteria of the marketing campaign based on the forecast data.