Six rooms, a group leaving on a Tuesday and another arriving on the Thursday, and one cargo boat in between.
The list came in on the Monday evening, which is exactly what this site is for. It was priced, transferred and made up before the boat had finished unloading, and the fresh part of it was in their kitchen by noon on the Wednesday rather than after the counter had sold through it.
What made the difference was ordering before the boat instead of walking to the shop after it. Ordering after the boat means taking what the island has not already bought, and on a Wednesday afternoon that is not very much.
They have ordered the same way every changeover since, and they have stopped keeping a month of tinned goods in a room they would rather rent out.