The Spark-n-Fizz, Bess Sterling's shop where she sells fizzy juices and upgraded appliances
(Just starting out, pretty bare-bones right now. I'm happy that I got a run-down look, not easy in sims!)
https://i.postimg.cc/KvkhdnB4/spark-customers.png
I'm pretty new to retail gameplay so I'm still learning as I go.
So far, the most significant tip for Bess has been that when she sells an item, she can just click on the item's marker to restock it, and the restocked item is the same in every way as the item that just sold. She doesn't have to go to the fizzy station and make more juice. She doesn't have to do the same upgrades on the next appliance. Once she's upgraded an appliance to start with, all replacement appliances have the same upgrades.
Restocking takes a little time but not as much as fizzing or upgrading from scratch.
I haven't yet been successful in having customers buy bottles of fizz from the fridge. They will buy six-packs of it off a table. I'm not sure if there is a glitch at work or if the other items are just more attractive.