Why It Works: How McDonald’s applies behavioural science to sell fries

Last time we met, we went out for a steak dinner. The time before that we enjoyed a breakfast coffee. Now it’s lunchtime, and we’re feeling a bit more burger-y, so we’re heading to McDonald’s.

Let’s see what behavioural science tactics we can spot in the wild over there.

Scarcity sells

Scanning the menu, something interesting immediately pops out. Halloumi fries. Mmm. Suddenly that’s the thing I fancy eating more than anything else — and it’s labelled “limited time only” so I’d better get those in while I can.

What’s going on here? There are a couple of interesting psychological principles at play.
First, tagging a menu item with “limited time only” makes it scarce, instantly putting it on the table for consideration because we know this might be our only chance to try it.

Sure enough, there’s evidence to show that scarcity affects our behaviour in purchasing situations. In 2012, Seung Yun Lee from Hanyang University showed participants one of two ads for a wristwatch.

Some ads used scarcity messaging, such as “exclusive limited edition” or “hurry, limited stocks”; others emphasised the large volume of items that were available, “New edition. Many items in stock”.

Participants were asked to indicate their purchase intent on a 9-point scale (1 = not at all likely, 9 = very likely).

Those who saw the scarcity messaging rated their purchase intent as 4.62, whereas the high volume group rated it as just 3.37 — that’s a 37% higher purchase intent, simply with slight tweaks to the messaging.

Why It Works: How Stoptober helps millions to quit smokingScarcity works because it imbues our decision with a sense of urgency. It sparks a fear of missing out, rooted in loss aversion — we don’t want to lose this opportunity. And it works remarkably well.

McDonald’s have been the masters of limited time items over the years. It first tested the strategy with the McRib, which was introduced to Kansas City diners in 1981.

Proving only moderately popular, it was removed from the menu. But the resulting McRib outcry gave the marketers new food for thought. Realising that adding time-limited items spurred demand, the McRib turned out to be the first in a roster of novel products.

So the carefully chosen wording alongside those halloumi fries are exerting subtle pressure on us, without us even realising.

But volume scarcity isn’t the only benefit of listing new menu items for a short time only.

Halloumi fries, fresh eyes

Not only does a limited time offer make us want something more, it also means the offer will end on a high.

Because limited time items get around the issue of habituation. That is our tendency to adapt to stimuli we’re exposed to frequently or for long periods. With repeated consumption, we become habituated to regular items on a menu — but listing certain options for only a short time doesn’t allow that to happen.

There’s some fascinating evidence to show that habituation affects satisfaction with our experiences, from a 2008 study by Leif Nelson and Tom Meyvis from NYU.

They asked two groups to test a massage cushion: one group received an uninterrupted 3-minute massage; the other had the same total duration, but split into two 80-second sessions with a 20-second break in between.

McDonald’s brings global menu to UK in first major post-LHF pushAfterwards, participants rated their enjoyment on a 9-point scale (1 = not pleasant; 9 = extremely pleasant).

Those who had a continuous 3-minute massage rated the experience as 6.05 out of 9.

However, those who took a 20-second break mid-massage gave a rating of 7.05 — that’s a 17% improvement in satisfaction.

This evidence suggests that we appreciate pleasurable experiences more if there’s an interruption. That break stops us taking the situation for granted. When it comes to halloumi fries, the first time we taste them, they’re amazing. By the fifth time, we might be a bit jaded.

But by removing the halloumi option from the menu at regular intervals, they vanish before we get bored – so we’ll remember them as delicious, and if they pop up again, we’ll give them another try.

We thought we’d order a salad, but…

We bought a burger and halloumi fries. Of course we did.

We’d had good intentions on the way down there. We clocked the salad on the menu. And then we ordered fries anyway. But the salads had served a purpose – they helped us to justify our visit for lunch.

And there’s another interesting bias at work here: time inconsistent preferences. That is, what we want for our future selves differs from what we want in the moment. So, salads are a great way of getting customers through the door, allowing them to plan a nice healthy lunch. Whether or not they order the salad, well, that’s another matter.

(They don’t. A tiny number are sold compared to fries).

Evidence for the mental games we play comes from Daniel Read and Barbara van Leeuwen from Leeds University, who conducted a study in 1998 into the effects of timing on future food preferences.

Two hundred employees at a Danish company were assigned to one of two groups. The first group were asked to select a snack (an apple or chocolate), which they would receive to eat in a week. The second group was asked to choose one of the snacks to eat there and then.

Dyson and the importance of being transparent about your effortsNearly 50% of participants chose the apple when the snack would be coming in a week. However, when choosing what to eat at that moment, 81% went for the chocolate — only 19% actually wanted an apple.

It’s clear that when considering the future, we pick what we feel we ought to. But when choosing for now — we go for what we actually want, not what we should want.

By offering salads on the menu, McDonald’s allows us to head over there for a healthy weekday lunch. We’ll have grilled chicken and fresh salad, we tell ourselves. In reality, what we fancy when we get there is often something quite different, in part, because of the biases discussed above.

Offering the healthy option isn’t always about what people choose — it’s about what helps them feel better walking through the door.

No sign of a sign

We notice that the menu features £ signs, but I recall from a recent trip that in the US, they do things differently. Over there, the dollar signs are absent. And that’s probably a sensible business decision.

It’s a tactic that crops up in the food industry a lot — we spotted it at Flat Iron last time. And there’s plenty of evidence that reducing the “pain of payment” reduces price sensitivity, making customers likely to spend more.

Specific experiments show that the pain of payment can be reduced by removing currency signs from menus, like the 2009 one from Sybil Yang at Cornell University and colleagues.

When 201 café customers received one of three menus, those shown plain numbers (e.g. 20) spent 8% more than those who saw prices written as “twenty dollars” or with a dollar sign (e.g. $20.99).

So, like Flat Iron, McDonald’s in the US is probably upping the average spend by leaving off dollar symbols, and maybe this is a move the UK branches should consider too. It’s a tool that can clearly work in different dining settings, from fast food joints to premium eateries.

Lessons from the burger field

When you’re persuading people to part with cash, some of the oldest tools in the marketing playbook are still around for good reason. Don’t neglect the power of a “limited time” item, remember your customers enjoy the potential to do the right thing — even if they don’t follow through in the moment — and, like US McD’s seems to know, don’t show pound signs on your prices.

So, we came in craving a burger, shunned a salad, flirted with a halloumi fry, and left with some useful lunchtime BeSci lessons. Digest at your leisure.