Q&A: Businesses & Hobbies

You will need to restock Retail Surfaces when they are sold out, but you can slow down sales in a few ways. Any businesses that have a food/drink counter can continue serving default food/drinks from the object, even if all other food stock on the premises has sold. Services (like tattooing, massages etc) also don't sell out, just make sure you set your Owner/Employee to tend any service items (if you  haven't already done so) before you rotate away. Items that don't need a stock or a service sim, such as skill objects and games, are always available for use even if there is nothing to buy and no active services when you visit.

* When the lot is not loaded there will be no sales, so stock level should remain the same. You could play several households in a row without visiting the business, and nothing would have sold. You can limit visits to/time spent at the lot to slow stock depletion.
* When playing the lot (as the Owner), you can Disable Sales on Retail Surfaces to stock them without Customers constantly buying things, but can still  keep the business open for other services.
* If you want Customers to still occasionally buy things (at a much slower rate), you can Enable Sales on the Retail Surfaces, but don't set/unset Browse and Buy Items as a Business Activity (sims aren't pushed to buy, but still do occasionally of their own accord). By the time you rotate away, you should have full shelves if you use one/both of these methods.
* You can also consider selling copies of crafted items, rather than the originals. Copies are  fast to produce, so it's an easy way to refill shelves. Copies usually have worse quality, but there are various ways to improve item quality in game. They also sell for less than the original, but if you are making copies quickly, you also don't need to slow down sales to keep shelves full.
* Time to rotate? Enable Sales on your Retail Surfaces, if they are Disabled. If you forget this step, you won't be able to buy anything placed on Retail Surfaces when you visit as a Customer.
* Move to the next household.
* Now you can visit Business 1 with Household 2, but as a Customer. As the lot has not been loaded, it should have all it's stock from before set for sale. Watch the other Customers buy things... The purchase rate should be slow enough that you might never see them buy things, nothing like the fast-paced sales rate it would be with Browse and Buy Items selected.