1. An apparatus comprising: a processor; and a data storage device in communication with the processor, the data storage device storing instructions configured to direct the processor to: receive an indication that a customer accepts an offer from a second vendor for a subsidy of a purchase, at a reduced price, of at least one item from a first vendor, the at least one item having an associated total price, and the offer defining an obligation for the customer to fulfill, the obligation being in addition to payment of the reduced price; after receiving the indication of the acceptance of the offer, charge the reduced price for the at least one item to a credit card account of the customer; determine that the customer did not fulfill the obligation; and in response to determining that the customer did not fulfill the obligation, charge to the credit card account of the customer at least the difference between the total price and the reduced price.