@Wholesome_Goth
Yeah, there’s a kind of upright freezer thing. I have one in my store and it seems fairly useless, sale-wise, but I’ve seen plantains fly off the shelves in one of James Turner’s letsplays.
I have a couple of shops. The current one is owned by Caleb Vatore and is vampire tomes, plasma packs, trinkets from Paranormal stuff (via showhiddenobjects), and the bakery case full of his girlfriend’s Dragonfruit. It’s not quite the Strangerville Curio shop but it’s… odd. 😀 The other is a witch’s magic shop where she sells potions and potion ingredients, and also does juice fizzing in the back and sells cowplant berries and Dragonfruit in the bakery case. Honestly the Potions are flavor and we’re living on produce and fizzy juice (mostly produce). She basically copypastoed her Potions for the shelves and we restock. (I just added the magic Tomes and uploaded it to the gallery and popped it into my starter save.)
So. Do decorate, it helps. There are also signs under retail items that improve foot traffic. There are perks that help after a while, and you can also advertise. The witch has an employee that does nothing but clean unless there’s a rush because things immediately become filthy. (Caleb’s girlfriend and her teen brother sometimes come in and clean or restock.) The Cursive sign that's on every single retail lot, including mine? that's one of the items that attracts people to the store ("curb appeal").
Restocking is a pain. You make the most profit selling items you create or grow.
People often gravitate to the cheapest item in the store and only buy that. Try temporarily setting other items not for sale so people have a choice of food, food, or a $12K violin (just kidding… mostly). That said, Dragonfruit just flies off the shelves in my stores.
I suspect that people would absolutely go upstairs. I have a vet clinic that I have to lock doors on to keep customers out of it. Ditto a restaurant with a little apartment over it.