I'm going back a long time, I know...but individual grocery store managers of the chain outfits used to have the freedom to discount overstocked items, offer up grocery items including prepared foods that were in line with the buying habits of his usual customers.
Where I worked in the biz as a lad, a good portion of the clientele was Italian, Jewish, and Polish. Stores featuring hot foods was a long time in the future, but the Head Butcher was free to add this or that prepared food to the deli case and the fresh meat was cut off the carcass in tune with what would sell, the Produce Manager could add produce that the customers had a favor for.
The Store Manager could expand and contract shelf space to suit his customer's preferences. Actually, that was done by the stock boy who filled a particular aisle. We 16+ year-olds would order the replenishing stock, and were trusted to know what was selling and what was not. You were even allowed to work off excess stock on the now highly-coveted aisle end displays.
Much if not all of that has disappeared IMO - every inch of shelf space is fought over by vendors, the controlling corporation extracting the last ounce of money (or "considerations") from the vying vendors. I may be wrong here - perhaps someone in grocery store management could chime in...
I have fond memories of my time working in grocery markets. Those good people taught us youngsters about business, trusted us and gave us responsibilities, and sincerely wanted us to have a career in the business.