If Apple can ship 40,000,000 units a quarter, every quarter, that puts minimum capacity at roughly 400,000 units a day. Minimum. We know they can do this. If they are now quoting shipping times of 30 days from now, how many units in the backlog? At the minimum capacity number, that would be 12,000,000 units on back order, but we all know the 40,000,000 per quarter is not a maximum number. How many units a day do you think is maximum capacity? At 500,000, that would equate to 15,000,000 currently on back order. At 600,000 that would be 18,000,000.... Now the ship date and back orders won't be exactly accurate, but it has to correlate to some degree.