That depends on the type of delivery you choose. When it comes to domestic parcels, if your item was sent by express or courier post and you expect delivery on the next or even the very same business day, you might want to track it to make sure it was delivered to addressee as planned. If it was less-then-urgent mail and you chose it to be regular delivery, tracking AusPost might help you make sure the delivery is progressing smoothly and there are no hitches along the way.
If you’re dispatching an international parcel, tracking will help you make sure it left Australia safely and was not stuck at customs for any possible reason. The same goes for parcels coming to you from overseas. As soon as they get to the country and are registered at customs you can keep an eye on the parcel. Just check AusPost tracking for your item and in case there’re any problems with delivery, you’ll be able to solve it in no time with the help from company’s customer support.