Software has to integrate with the register so that when certain amount is paid, the software writes the information down to the card of the costumer. Card has to be read by a bar code scanner and information such as (name,email adress,adress,telephone number,etc) has to be written on it.
Also, software would have to print out confirmations that will be customizable by the consumers issuing them.
In advance, newsleter should be automatically created when products are put on sale and mailed to the costumers having loyalty card.