Yeah but the interaction that is done in Australia is not part of the business chain. The catalogue was not mailed by my store. Someone else (an ISP, in this exercise) took it from an available stand in Italy and imported it (on their own) to Australia. (The closest I can think of to the material representation of "mailed catalogue" in this exercise is if I intentionally uploaded a copy of my .it website to an .au hosting)

For another analogy: if I were to post an Italian job offer in Italy, not only I am not subject to Malaysian (or Australian) labour law, but a third party in Malaysia reproducing the job offer there does not change that fact either. It's their copy, and act-of-copy, of the job offer that is subject to Malaysian law, at best. And this should hold true regardless of the nature of the message: mere emission of the message can not be constituted as consecration of a legal responsibility towards any potential listener. If that was the case, it would be impossible to make any political, religious or scientific speech lawfully, as surely a law is being broken sometime, somewhere and a message can by its nature outlast the act of emission.