An empty shopping cart never stays empty for very long. Shoppers can’t help but want to fill up whatever space they see available, and the more room you have in your cart, the more items you’ll buy without even realizing it. None of it is accidental or just pure luck for the grocery stores – they’ve known about this behavior for decades and have designed their carts around it. Cart sizes have actually grown to almost double what they were back in the 1970s!
When shoppers have plenty of space available in their cart, they usually give themselves permission to add just one more item and then maybe another one after that. Before they know it, they’ve gone way past the mental budget that they had in mind when they first walked into the store. Online stores have picked up on this concept too, and empty-looking online cart pages combined with free-shipping thresholds tap into that same fill-it-up instinct that physical retail has been relying on for decades.
Let’s talk about how something as basic as the cart size can increase your sales!
How Empty Space Makes You Spend More
Push a cart around with just a few items that rattle at the bottom, and your brain reacts in an interesting way. It looks at all that empty space and sees it as a problem that needs to be fixed. The room left over gives you this persistent feeling that you should probably go ahead and fill it up.
It works like a visual checklist that reminds you to add more. The cart itself is a big empty container, and all that unused space almost seems like it needs to be filled. Studies have proven this, too. When shoppers use bigger carts with plenty of open space, they wind up grabbing many more items than they meant to buy when they first walked in.
Your brain reacts to all that empty space in the cart. A half-full cart feels unfinished – like your trip isn’t quite done yet. All that extra room makes you feel like you should grab a few more items before you check out. A smaller basket that’s already full feels done and ready to go.
Grocery stores actually picked up on this behavior decades ago. Once they made their shopping carts bigger, customers bought more groceries with every trip to the store. The pattern is pretty reliable – give shoppers more space to work with, and most of them will find a way to use it.
Physical cues usually influence how we shop, and most of us respond to them in similar patterns. An empty cart almost feels like permission to continue, and a full one tells you it’s probably time to wrap up. Retailers use this psychological trigger because it changes shopping behavior and sales.
How Your First Purchase Changes Everything
Once a shopper drops that first big item into a large cart, something interesting happens in their mind, and each product they add after that doesn’t feel like as big of a buy because the cart still has all that visible empty space. It’s almost like that first item gives them a mental green light that makes it easier to justify adding more products to the cart.
Ravi Dhar and Joel Huber actually studied this behavior and ended up proving what most store owners already knew from experience – when you put that first item in your cart, it gets way easier to talk yourself into adding a second one. After you’ve made that first buy, the next one just doesn’t feel as big anymore. And when your cart still has plenty of room left in it (as in, it doesn’t look stuffed or packed tight yet), you can drop in another item or two and it doesn’t register as that big of a choice compared to trying to jam something into a smaller basket that’s already packed.
A shopper who puts bulk paper towels or a case of bottled water in their cart at the start of their trip has already committed to a particular price point. Once they’ve spent $30 or $40 on that first item, another $3 for a bag of chips or a box of cookies on their way to the checkout barely registers. Everything else in the cart seems like less money compared to that first big item.
This momentum just goes on as they continue to shop and browse around the store. When they look down at their cart, there’s still plenty of room in there and on some level that tells them that they can add more. Once they’ve already committed to that first big buy, the next one doesn’t feel nearly as hard to justify. They’re still keeping track of what they’re spending. But each single item seems like less when it’s sitting right next to everything else they’ve already decided to buy.
Cart size actually plays a really big part here. A bigger cart gives shoppers a lot more room to fill it up before it starts to look too full in their mind. All that extra space creates more opportunities for them to grab items that they probably would have missed if they were carrying a smaller basket.
Why Big Carts Make You Buy More
Costco built its entire business model around bulk shopping, and if you’ve ever pushed one of their carts around the store, you already know that they’re huge – each one is nearly twice the size of a cart you’d find at most other grocery stores. Costco went with this oversized design for a specific reason – they want you to think bigger as you shop, and the cart itself is the first way that they push you in that direction.
A regular shopping cart at your local grocery store can hold about a week’s worth of food for most families, maybe a little more if you’re careful about how you pack everything in. If we’re just talking about paper towels, one standard cart could probably hold around three weeks’ worth of them. These warehouse carts are a different animal though. When you wheel one of these massive carts around the store, your whole sense of what counts as a “normal” buy starts to change. A 48-pack of granola bars actually seems pretty reasonable with all that empty space in front of you.
These carts cost Costco a lot more money up front than standard ones do. A cart that’s almost twice the size will weigh more, which makes it harder for the employees to move around the parking lot. Each one also takes up more space when they have hundreds of them sitting outside. The frame has to be built with stronger welds, and the wheels need to be much sturdier to carry all that extra weight. Costco wouldn’t spend that money on bigger carts unless they had a good reason for doing it.
The size of the cart that you grab will actually influence your shopping trip, and it sets up an expectation in your mind before you’ve even made it to the first aisle.
The Choice Between Baskets and Carts
Most grocery stores will set up hand baskets and full-sized shopping carts right at the entrance. It seems like a pretty basic convenience – grab a basket if you only need a few items, or take a cart when you’re ready to stock up for the whole week.
A shopper walks into the store with a mental list of maybe three or four items. A basket seems like the obvious choice for a quick trip like that. But the shopping carts are right there in the same place, all lined up and ready to use. The shopper pauses for a second and rethinks their first choice. It might make sense to grab a few extra items since they made the trip anyway, and the cart gets picked instead of the basket.
Once a shopper makes that switch from the basket to the cart, it changes their behavior. A cart gives them enough room for those extra items that would never fit in a basket. It also removes that built-in stopping point you run into when a basket gets too heavy or just too awkward to lug around the store. A cart lets shoppers pile on items without any physical discomfort to slow them down.
Retailers have seen this pattern and some of them have started to adjust how they make the baskets and carts available to shoppers. Walk into a store and the baskets are sometimes placed a bit farther back from the main entrance than where they used to be. Sometimes you’ll find not as many baskets out on the floor compared to what seems right for the busy afternoon rush. The carts stay right up front where anyone can grab one without even breaking stride.
This setup doesn’t happen by accident. What you’re seeing is called choice architecture and it’s already working on your behavior before you’ve even taken your first step down the aisles. Both options technically exist – the positioning just makes one path way easier to follow than the other. Almost everyone ends up taking the easier path.
These same principles extend well past the physical retail stores. Cart size and choice architecture matter just as much when you shop online. Any big website or app uses these exact moves to decide what ends up in your cart and how much you actually spend.
How Empty Carts Make You Buy More
Online retailers have figured this out as well, and the way they design their websites shows these same psychological principles. Check out the shopping cart icon on most e-commerce sites and you’ll see that it shows whatever items are in there (usually just one or two) with lots of empty space around them. That empty space gives you a visual cue that works on your psychology in the same way an oversized physical shopping cart does when it has just a few items rattling around in the bottom of it. Most online shopping carts will also show you a “saved for later” section right below the items you’ve already added. What this does is create even more white space for you to look at, and it gives you another area on the screen that looks like it’s waiting to be filled with more products. Those empty slots just sit there on the page and practically beg for your attention.
Progress bars work on this same psychology. When a website tells you that free shipping kicks in at another $15, it’s pulling on that natural drive that we all have to finish what we started. The bar sits there half full, and something in your brain desperately wants to watch it reach the end point.
Most of the online techniques you’ll see are actually inspired by what traditional brick-and-mortar stores figured out decades ago about cart sizes and consumer behavior. The screen in front of you is an online container just like a physical shopping cart is in a store. When you see all that empty space on the screen, the same mental process kicks in and your brain starts to fill it up with possibilities pretty fast. Online shopping carts actually have a psychological edge over physical baskets in a lot of cases, and it’s all because of that persistent empty space.
Every time you look at your cart, that void is still sitting there staring back at you. With a physical basket at the store, you’d have to actively look down or pause to see what you’ve already grabbed.
The website keeps that reminder right there in front of you the whole time, and it doesn’t go away until you either fill it up or finish your order.
Why Big Carts Can Backfire
Carts that are too large work against you in multiple ways. Cart size affects shopping behavior. A customer with a large, roomy cart will usually add a few extra items early on in their trip. All that empty space is asking to be filled and creates purchases that weren’t on the original shopping list.
At some point during the trip, they’ll look down at everything that’s accumulated. The cart that was supposed to make shopping easier is now a visual reminder of how much they’re about to spend.
Cart abandonment happens all the time during active shopping trips, way more frequently than most stores track. A customer will leave their oversized cart in the middle of an aisle and walk straight out the door because handling it seems like way too much work. Cart size plays a weird psychological role in this. A basket that looks mostly empty makes some shoppers second-guess their purchases – am I buying enough? A cart that’s packed full creates its own set of problems and can make shoppers worry about overspending or whether they’ll even have room at home for everything they’re buying.
Returns are another issue you’ll have to handle, and it crops up after the sale is already done. Customers take their purchases home, unpack everything and then start to have second thoughts about what they bought. Each return that comes back cuts directly into the extra revenue you were expecting to get from those bigger order sizes.
The experience in your store can change because of this as well. Large carts usually make a retail space feel more like a warehouse and less like a welcoming place to shop. Customers will connect those giant baskets with bulk purchases and discount stores – and if that matches your brand, great! But maybe you’re going for a more curated or boutique experience. Those big carts might send a different message than the one you’re trying to communicate.
Taking it too far means you’ll either lose the sale or you’ll have a lot of returns that’ll wipe out whatever extra money you made. The best size falls between being too cramped and being too roomy, and you’ll need to test out a few different options and watch how your particular customers respond in order to actually find what works for your business.
Convert Your Foot Traffic Into Extra Revenue
The shopping experience at your store tells customers plenty about who they are and why they buy what they buy. Cart size shapes customer behavior, just like your bigger goals do. All these elements work together to make customers feel relaxed about spending money. Get it right and customers walk out happy with their purchases instead of feeling pressured into buying items they didn’t actually want.
It works because you don’t have to overhaul your product lineup or drop your prices to get better results. You just use the way that customers make buying decisions anyway. Visual cues and the psychological momentum that builds up as they shop are always there in your store – even if you’re not paying attention to them. The choice that matters is if you’re going to use those patterns intentionally to make shopping better for your customers and to grow your sales at the same time.
Your customers have their own preferences and habits that might be different from another store down the street. Bigger carts will work great for some businesses and others will find that baskets and carts make more sense for their setup. The best strategy is to watch how your customers actually shop and make changes based on what you see happen right in front of you.
To make your foot traffic more worthwhile, we built ecoATM kiosks around one core idea – to create new opportunities from the customer visits you already get. Our kiosks give customers a reason to stay at your location for longer and add a revenue stream that fits right alongside your main business. We’ve processed millions of devices and helped to create positive customer interactions over the years.
How a partnership works for your goals will be different for everyone. Maybe you want to bring in more customers through the door, or maybe you want to show customers that you’re about responsible technology practices, or maybe you just want another income source that doesn’t take much work from you. Whatever you’re after, we can help make it happen. Contact us to learn how an ecoATM kiosk fits into your space and creates value from day one.
