So what if when you set a sale to a certain person, it gives them some sort of notification.

support. It'd be easier rather than setting them up and going back to PMs or Forums to tell them.

I suppose I do support, but there would have to be a way to block/disable notifications from this.

I am the kind of reckless genetic tester that's willing to take on batches of seventy pets at once. I also check my notifications for pet sales and expired sales (I have a sales thread I try to keep up to date), and don't want to dig through seven pages of "XXX set up a pet for you!"
(Also, this could be used as spam by setting up lots of pets for obnoxious prices to people specifically to flood their notifs.)

Yes. I've promised to go e people pets and 27 days later... Sorry, you can't do blah blah blah since this pet I'd up for sale. And I don't want to track EVERYONE down!