1. A method comprising: providing a computing apparatus comprising: a transaction handler to process transactions of an account holder, a communication portal, coupled to the transaction handler, configured to receive communications from a merchant computing device regarding advertised incentives for display in a shopping cart of the merchant, and at least one database, coupled for access by the transaction handler, configured to store registration information for advertised incentives; providing, by the communication portal, a merchant interface to allow the merchant to create an advertised incentive program by specifying an advertised incentive program configuration, the merchant interface further allowing the merchant to instantly activate the advertised incentive program and to instantly deactivate the advertised incentive program, the advertised incentive program configuration defining an advertised incentive and defining what transaction is qualified for the advertised incentive, and the merchant interface further allowing the merchant to disable the advertised incentive based on receiving, from the merchant computing device, a change in configuration for the advertised incentive; receiving, as part of the advertised incentive program configuration, via the communication portal, an advertised incentive image and an alternate image; storing, in the at least one database, the advertised incentive program configuration and an indication that the merchant has activated the advertised incentive program; receiving, from a server that provides the shopping cart, an assigned identifier for the advertised incentive; sending, by the transaction handler, to the server, based on the advertised incentive program configuration, content for an advertised incentive banner of the shopping cart for display to the account holder, the content to include the advertised incentive image when the advertised incentive is enabled and to include the alternate image when the advertised incentive is disabled, the sending the content to control the shopping cart in a website of the merchant so as to display the advertised incentive image when activated by the account holder in the shopping cart, and to enable a transaction using the advertised incentive when a purchase device of the merchant generates an authorization request for the transaction; reserving, by software rendering the website, an area in the shopping cart for the advertised incentive banner; providing, by the transaction handler, the content directly to the reserved area; receiving, by the transaction handler, while the advertised incentive program is activated, the authorization request from the purchase device to authorize a qualifying purchase transaction, the qualifying purchase transaction qualifying for the advertised incentive according to the advertised incentive program configuration; executing, by the transaction handler, the advertised incentive with respect to a payment account of the account holder, upon which payment account the qualifying purchase transaction was authorized; and in response to receiving the authorization request, sending, by the transaction handler, to the purchase device, authorization data to cause the purchase device to complete the qualifying purchase transaction.