For most of our products, they are FLAT PACKED so we can send out by couriers.
Some products if not that big, even they are not flat packed, we can still send out by couriers. 

For those big things, esp some woodedn furniture like tall boys, they are way too big to be sent by couriers, so we have to use a specified CARRIER to provide national wide shipping service.

Normally, couriers is more fast but it will be very expensive when the parcel going big and heavy. For most of the mall stuff, courier is more cost efficient than carriers.