1. A card vending system that comprises a plurality of vending machines each of which includes a product dispensing mechanism for dispensing to a purchaser in possession of a vend card a product selected by the purchaser; said card containing readable indicia; and a card reader mechanism into which the purchaser inserts said card to effect a purchase transaction, including means to read the indicia on said card, means to actuate said product dispensing mechanism, card controller means to interpret the indicia read from the card to ascertain the purchase credit balance available to the purchaser in possession of the vend card and to write onto the vend card a new purchase credit balance available to said purchaser; said card reader storing transaction data for the associated vending machine, including the number of purchase transactions and money value of the transactions on said vending machine; a plurality of meter cards each associated with a respective one of said vending machines, each said meter card being insertable into the card reader mechanism of the associated vending machine, and having recorded indicia thereon including command codes to command the card reader to write onto said meter card the transaction data stored in said card reader mechanism; and a transaction terminal which includes computer station means for receiving, storing, processing and displaying the purchase transaction data for the vending machines in the system; and a meter card reader mechanism coupled to said computer station and into which said meter cards are inserted for transferring from the meter card to said computer station a vend machine identification code and the purchase transaction data for the vending machine associated with said meter card.