Cost efficiency dictates packaging size
Rest mail covers odd shipments that are too large to be considered letters and too small to be considered parcels by conventional standards. For example, items being shipped as large letters because it’s cheaper, even though parcel would have been the better option from a packaging perspective.
The larger cause for concern for distribution centres, though, is the occurrence of tiny parcels. The strong competitive forces in e-commerce—combined with postal subsidies favouring mailers outside Europe and North America—drive down international shipment fees, making it a relatively small proportion of the total purchase price. As such, instead of ordering more items at a time, we as consumers are increasingly willing to order single, smaller purchases, which are smaller than postal services’ conventional ‘small parcel’ measurements. Some of these orders are minuscule, like a set of ear plugs or PC spare parts.
The mailers of these tiny shipments, typically global e-tailers, are looking to keeping the packaging—and postage costs—to an absolute minimum. A common example is to ship an item with packaging that can just barely contain the address label, or worse: wrapping the address label around two sides of the parcel allowing for even smaller packaging.
Small parcels generally fall into the rest mail category if their width and length don’t exceed the size of an A3 sheet (29.7 x 42.0cm); a folded t-shirt for example. For some distribution centres, small parcels make up to 80 percent of the total items handled – up from just half less than ten years ago. This change is a natural consequence of our online shopping habits: we tend to buy more books than couches online.