A client who was planning an event for prospective PhD students asked me to attain a list of people who had completed graduate school, worked in military or technical/professional professions, and lived in the DC area.
Upon reviewing their invitation package, I noticed the reply envelope did not have an automation barcode (which corresponds to the reply address) or the FIM bars. I made a visit to the postal service website and obtained the barcode artwork and provided to the printer.
By adding the barcode to the reply envelope helped to save them approx $700 on a 35,000 piece mailing.
The difference is approx 2 cents if your reply envelope or card, is not automation compatible.