Self-order kiosks: do they really grow the basket?

Self-order kiosks usually do grow the average check, but not by 30%: the most careful field studies, run by the University of Hamburg on real fast-food orders, found 13% to 16% more spending per order [8][9]. The popular “McDonald's kiosks lift checks 30%” has no study behind it that we could find.

What matters more for your restaurant is why kiosks sell more. Researchers point to two causes: the kiosk suggests an add-on to every customer, and customers stop feeling judged. Neither one needs a screen, and you can put the first to work on your phone orders tonight.

Do self-order kiosks increase the average check?

The big chains say yes, without publishing their methods:

• Shake Shack (2024): kiosk checks run “a high teens percentage” above checks from its other in-store channels, driven by stronger upsells, according to its CFO [1].
• McDonald's (2018): “we get a higher average check” at kiosks, the CEO told investors, with no number [2].
• Wendy's (2019): kiosks bring “slightly higher check sizes,” its CFO said [3].

The independent measurements come from two studies by researchers at the University of Hamburg, in Germany, using real transaction data rather than surveys:

• 2019: 13% more per order. At a fast-food restaurant, customers spent 13% more per purchase at the kiosk than with an employee, after controlling for self-selection [8]. That correction matters: kiosk users may not be the same people who line up at the counter, and without it you'd be measuring the customers as much as the kiosk.
• 2023: 14% and 16% more. Using transaction data from 20 restaurants of a fast-food chain, the same team found customers spent 14% and 16% more at the kiosk than at the counter, in two studies [9].

All the figures at a glance:

Chain figures come from their own registers, and nothing says they correct for who chooses the kiosk. The range to remember is the studies': 13% to 16% in fast food.

Where does the “30% higher check” kiosk stat come from?

Search for kiosk statistics and you'll soon find “McDonald's saw a 30% higher average check,” often paired with “20% of customers who didn't order a drink added one.” We traced it back:

• The oldest trace we found is an August 2018 column in The Green Sheet, a payments trade magazine, written by the CEO of Apptizer, a company that sells kiosk technology. It cites “a McDonald's self-ordering experiment” with no source, no date and no method [5].
• McDonald's never put a number on it in any statement we read. In 2015, its CEO said every McDonald's in France had kiosks, handling more than 40% of orders at busy times, and that checks were higher because customers could “browse the menu for a little bit longer” and “feel a little less pressure” [4]. In 2018, he said much the same, again with no figure [2].

The takeaway: don't use a number with no study behind it to work out a kiosk's payback. The real measurements come in at about half of that 30%.

Why do customers spend more at a kiosk?

The Hamburg researchers see two causes working together [9].

1. The kiosk suggests something to every customer

Kiosks automatically offer other products and consistently ask, for example, whether you'd like a coffee with your meal. A kiosk never gets tired, never rushes and is never afraid of bothering anyone. Shake Shack credits its kiosk lift to better add-on prompts, like an extra patty or bacon [1].

2. The embarrassment goes away

In front of a screen, people feel less observed and judged, the researchers explain. They also order more indulgently: kiosk orders contained 32% more sugar [9].

Researchers at Duke and the University of Toronto measured the same effect at a North Carolina pizza delivery restaurant [6]: 160,168 orders from 2007 to 2011 [7]. Once online ordering launched, web orders included 14% more special instructions (combined or split toppings) and about 100 more calories than phone orders [6]. As one of the authors put it [6]: “Online, you're not making anyone wait while you place your special order. No one's judging you.”

The restaurant's website made no recommendations at all [7], so the gap didn't come from suggestions. The authors put it down to less “social friction”: the fear of being judged, or of holding people up.

Should you add a self-order kiosk to your restaurant?

If you're considering one, ask four questions before you sign:

1. Will it suggest anything? Without well-set add-on prompts, you lose the first cause of the lift. At Shake Shack, the gains came with better upsell prompts [1].
2. Where does the vendor's percentage come from? Ask for the time period, the number of restaurants and whether they controlled for who chooses the kiosk, as the 2019 study did.
3. Who will use it? A kiosk only serves people standing in your restaurant. Phone orders never touch it, and neither does a call that rings out (see what a missed call really costs).
4. How will you measure it? Compare your average check on the same days and hours, four weeks before and four weeks after. Not every chain sees a big gap: Wendy's spoke of “slightly higher” checks [3].

How do you grow phone orders the way a kiosk does?

You can copy the method, not the number: we found no study measuring what consistent suggestions do to phone order size, so we won't promise you 13%. But both kiosk levers work on the phone.

• Suggest on every call. One suggestion, targeted at what's missing (a drink, a dessert), after the order. The method and the math are in our guide to suggesting a drink on the phone.
• Let callers take their time. The pizza study shows it: on the phone, talking to an employee, people spell out less. Never rush the caller, and read the order back before hanging up so they hear exactly what goes to the kitchen and can fix it.

That's where an AI voice agent helps a small restaurant: it applies the same rule on every call, without awkwardness or forgetting, even in the middle of the rush. Soleir, for example, can suggest a drink or a dessert once, and only if the order doesn't already have one. When a caller hesitates, it offers two or three items from that part of the menu, and it reads back every order before sending it to the restaurant. It also tells callers it's an AI at the start of the call (see what diners want from an AI phone agent).