How are winning postcodes selected?
At draw time the server selects at random a postcode from the database of all those entered.
We pick one postcode from all the eligible members (using their membership ID, their postcode and other details confirming eligibility, so the draw is actually taken from the database of active member's account ID numbers), then mark that person and all the other eligible members with the same postcode as potential winners.
It's like putting your name and phone number on a raffle ticket. When they pull out the raffle ticket, do they read out the number on the ticket, the name or the phone number? ... It's all part of the same process. It's similar when we choose postcodes. All that matters is that only active member's postcodes are entered into the draw.
The server has no geographical bias.
Each draw is reset - so even if your postcode has been drawn previously, it has the same chance of being drawn again.