I have a simple theory about any item that is shipped by any method.
The more you want it or need it, the longer it takes. If you don't care when it gets to you, it will be there overnight.
My wife ordered a snap on keyboard-cover for her iPad last week. She wants to play with her new toy and it has still not arrived. Last Saturday we were in Enid and her mom said she would like a new iPad since her iPad is a version one. My wife orderd an iPad Air, keyboard and new cables to be shipped to her moms house. The keypad for her mom's iPad showed up here yesterday. My wife clicked the wrong delivery address.

Ordered on Saturday afternoon, it arrives on Monday and it useless without an iPad to use it with right now.
The cables and showed up at her moms house but she does not have a iPad to plug them into.