Is it really free carriage?

As part of updating my web site I have been advised to state “ FREE CARRIAGE ON ALL ORDERS” as the price shown is the the price you pay. However this statement has always been a point of annoyance with me as I can’t see or accept that anyone can offer free carriage, it has to be paid for at some point. The adhesive tape, cardboard and delivery method all cost money and time, so how can it be free? The price you pay will have a cost of carriage in it (maybe subsidised depending on the order value) so I have decided to state on my web site that ”our prices are inclusive of carriage”.
Maybe next time I buy something that says “free carriage” I should phone them and ask how much cheaper the item would be if I was to collect, I’m sure most companies would offer a discount for collection.