Yep, there are 2 types of situations where the AC makes sense and I only thought of the mail order and selling it to a single customer at first. Then someone asked if they could send it out to a customer, get it back, send it to another customer, etc. and I thought that was a great idea! Depends on how your shop is setup, do you mostly do mail order with sending PCMs back and forth or do you sell a tune to a customer and then support it? An AC is good for both, great for the latter.