Rank "popular" by takings, not by how many you sold
A most-popular rail sorted by units fills up with cheap sides. Sort it by what each item actually takes and the same shelf starts paying rent.
Most QR menus now open with a rail of popular items. It is worth having: the first decision a hungry person makes is the hardest one, and a row of things other people already chose makes it easy.
The question nobody asks is what "popular" is sorted by. The obvious answer — how many of each item sold — is the wrong one, and the reason is sitting in the data of any kitchen that sells sides.
Units sold is a list of your cheapest items
Count units and the rail fills with fries, sauce pots and cans. Of course it does: they ride along on other orders, they cost little, and nobody deliberates over them. A four-pound side sold thirty times beats a signature dish sold ten times, every week, forever.
So the most valuable screen real estate on the menu — the first thing every guest sees — ends up advertising the items that need no advertising and carry the least margin.
Sort by money and the rail starts working
We changed ours to rank by takings: quantity times price over the last thirty days, per kitchen. A taco kit that took £37 from three orders now outranks a £3.50 pot of guacamole that sold eight times. The rail still shows what the room genuinely buys — nothing is invented — but the order now favours the dishes worth showing, and a guest who taps one spends more without being sold to.
Thirty days matters too. All-time counts freeze the menu of six months ago; a short window follows what this month's room actually wants, and a new dish can earn its way on in a fortnight.
What it is not
This is not personalisation and we do not pretend it is. It is the whole room's spending, shown honestly, ten items long, per kitchen rather than pooled across a hall — a bar's list should be drinks, not tacos with a beer at position nine.
One honest counter-case: if a cheap item genuinely is your signature — the thing people cross town for — a spend ranking can bury it. Watch the rail after you switch. Ranking is a default, not a law, and the menu is still yours to pin.