1. A method of operating a reward program in conjunction with a network, the network interconnecting with a plurality of merchant computers and at least one issuing bank computer associated with an issuing bank that issues a payment token to a user, the method comprising the steps of: a. providing, at the issuing bank computer, a reward account database that stores a plurality of reward accounts, each of said reward accounts associated with a unique combination of a user and a merchant for tracking rewards earned by the user associated with that reward account for transactions with the merchant associated with that reward account, wherein all reward accounts associated with a particular user are accessible with a user ID of a payment token associated with that particular user regardless of which merchant is associated with that reward account, b. a user executing a purchase transaction with a transacting merchant associated with a transacting merchant computer selected from the plurality of merchant computers by presenting a payment token for use by the transacting merchant computer for payment of at least part of the purchase transaction; c. the transacting merchant computer transmitting via the computer network a transaction request comprising a user ID as obtained from the payment token; d. the issuing bank computer adding rewards to the reward account in the reward account database that is associated with the transacting merchant and the user identified by the user ID; e. establishing on the reward account database a reward exchange account associated with the user; f. selecting rewards from each of a plurality of reward accounts associated with the user for exchange into the reward exchange account; and g. aggregating the selected rewards into the reward exchange account.