For younger shoppers permanently attached to their mobile devices online shopping carts act as shopping lists. That’s often the case as well for parents during back-to-school season.

It’s time for a brand new school year. That means a fresh slate, new clothes, and lists of school supplies that teachers ask their students to bring to class. Complaints on “mom blogs” seem to get worse every year, but this is an age-old issue. It may have been more than three decades ago, but I can still hear my mother asking me in frustration, “Did your teacher tell you where I can actually buy four red pencils with erasers? Or a clear plastic case sized to hold a box of 16 crayons?” Of course, the answer was no.

Today, things are much easier. Parents no longer have to look up art supply stores in the Yellow Pages or frantically call other parents asking where they found the elusive items. All they have to do now is enter the merchandise into search engines and sift through a few results. It’s easy to pop items into online shopping carts and continuously add new ones as more lists come home from siblings or from additional classes. Then, when you’re certain no more items are going to be added, hit the checkout button.

The sales opportunity of an open cart

Think of a digital cart just like their namesake physical carts. When someone is walking around a store pushing a cart, low-cost/low-risk products virtually  jump into the cart (70% of all purchases in drug/grocery stores are unplanned, impulse purchases). As shoppers see products that pique interest, they’re tossed into the cart with everything else and walked to the cash register. Digital carts behave in the same manner: Consumers are a lot more likely to add items to a cart that is open because they know they are going to convert on it soon anyway.

This provides a great opportunity for retailers and brands alike. Consider the mother filling online shopping carts with back-to-school supplies. While sorting through her social media feeds or reading news of the day sites, she comes across a banner ad for a new healthy snack that would go great in her kids’ lunchboxes. Or maybe it’s something for the dinner table, a new type of laundry detergent or a new cooling towel for her workout. On the one hand, she’s unlikely to make a special purchase for one of these low-involvement impulse purchases—but if she doesn’t act immediately, she is likely to forget about them the next time she is in the store.

But what if she could click on the ad and the product was simply added to the shopping cart she already has open for those back-to-school supplies? All it takes is a click or two and she’s done. Then at the end of the week, when she’s sure no more crazy supply requests are coming, she converts on the cart and the items come along with the back-to-school gear.

Capturing “carting” behavior windows

The notion of carting is nothing new for younger shoppers that are permanently attached to their mobile devices. To many of them, online shopping carts act as shopping lists. When they see something they are interested in, they simply add it to an online cart so it is already there waiting for them when they decide to buy. This is a boon for retailers and manufacturers because the carting action feels non-committal to consumers—but people aren’t as likely to take items out of carts once they have put them in. For many low-involvement sectors like consumer packaged goods, the path to shopping cart and path to conversion are pretty much the same.

More than 90% of all consumers say they use online carts to store items to purchase later—and over 50% of them have two or more carts right now with items in them waiting to be purchased. We know that these numbers are heavily weighted toward Millennials and Generation Z shoppers, who are most likely to view their mobile devices and the internet as extensions of their brains. But, Generation X is catching up fast, and extended shopping seasons where they buy a lot of merchandise in a short period of time—like back-to-school and the winter holidays—are when they start to dip their toes.

That’s what you can expect to see this fall. Carting behaviors will continue to develop organically among parents who realize their online shopping carts can store items over time. For many, this behavior will continue into regular grocery shopping as more traditional grocers expand their digital footprints. Manufacturers and retailers that partner together to enable the single-click addition of products from digital awareness campaigns to shopping carts will win with the busy back-to-school moms.

This article originally appeared on Internet Retailer.