I know there's a vendor feedback forum, but the last post there is July so I'm posting here.
For the first time in a long time, Amazon has degraded their service. I have Prime and could order just about anything via Prime. Not so anymore. They have Add-On items now. I presume they are lower priced items. They will only be shipped in an order or $25 or more or via subscribe and save.
I had recently changed my subscribe and save of Greenies Pill Pockets from the 8th to the 1st and thought it would ship on October 1st. No, they changed it to November 1st. So I go in to order the item and find I can't order it without spending $25.
Amazon has just decreased the value of my Prime membership drastically. I wonder how many items are like this? So far, have not been using my Prime for anything but shipping. If that is being limited, I'm not sure I'll remain in Prime.
I have never abused Prime, though I admit that when I order an item, usually a blu-ray, I don't worry about trying to order something else. I have never intentionally ordered items separately just to screw with them.