Before you settle on PFD, check their sister store nationalpetpharmacy.com. I use the auto ship on nationalpetpharmacy for canned cat food.
However I also keep an eye out to all the other on line stores (including PFD) I like to shop in, for promotions and sales that might save me a buck or two above what I save with the autoship. The autoship can be changed/postponed, customized, so if I find a sale elsewhere I simply change the date I want my next autoshipment from nationalpethoarmacy.
Hope that makes sense, I am very tired.
I have also used Amazon's subscirbe and save program. Same thing, very flexible.
You just have to stay on top of it is all.
Delivery for PFD is fast and reliable, as ii is for nationalpetpharmacy too.