Patent ID: 8719109

Claim:
A non-transitory computer-readable medium having stored contents that configure a computing device to perform a method, the method comprising: receiving an indication of aggregate demand among a plurality of users of an item transaction system to purchase an indicated item that has multiple copies; in response to the received indication of the aggregate demand, identifying multiple users of the plurality of users of the item transaction system who each has an available copy of the indicated item to sell and who is not currently allowed to sell items to the plurality of users of the item transaction system; determining other items that are available to be sold by at least one of the identified users and that are distinct from the indicated item; for each of the identified users, determining an effect if the identified user receives an opportunity to sell items to the plurality of users of the item transaction system, the determined effect being based at least in part on a change in an aggregate amount of supply for the determined other items among the plurality of users of the item transaction system that is determined to result from the available items of the identified user being made available for sale based on the received opportunity; and determining one or more of the identified users based at least in part on the determined effects for the determined one or more users and based at least in part on the indicated aggregate demand; and notifying each of the determined users of an opportunity to sell at least one available item to another of the plurality of users of the item transaction system.