Ordered an iPhone 6s 64GB, pristine, on Saturday a...

Ordered an iPhone 6s 64GB, pristine, on Saturday and was delivered the following Thursday, after the standard "we hope to deliver in 5 to 7 days...." email confirming the order. The phone works perfectly and is as advertised, condition as new. And daughter v happy her connection to the world is now restored.
What does slightly confuse me is that goods are advertised in such a way that it makes you think that they are there waiting to be sent out - otherwise how would the condition be known, for example? - so you do wonder what happens in the 4 or 5 days between order being received and being sent out.... unless the used phone market has more layers to it than I thought.