The most practical method of avoiding cancellations would seem to be to immediately mark the item as dispatched or to buy the postage label, effectively removing the option for buyer cancellation which, in my limited experience, is what most sellers are doing, private and business alike... I encounter this for approximately 90% of my purchases, when tracking is almost immediately available but the parcel can take several days to actually be scanned into the courier's system at pickup, shop or drop off location. In fact, cannot the generation of postage labels and tracking numbers be automated with Simple Delivery?