I ordered something from an Amazon seller that allows for Amazon Prime, which means two day shipping for free.
So the day after I order, I get a notice that it has shipped. Two days later, I get a email from the seller saying that the shipment would be delayed. Two days after that, the shipment arrives, clearly shipped regular mail.
So it appears that the seller claimed it was delayed so they didn't have to ship it fast.
I'm happy it got here, but a little annoyed since I pay for Prime so I can get things faster.