Why a Moving Screen Sells What a Poster Can't
Rachel has managed the same neighbourhood supermarket for nineteen years. Behind her office door hangs a stack of foam-board standees, curled at the corners, each one a promotion that ran for two weeks and then went nowhere. She's been pitched digital screens more times than she can count. Her answer is always the same: "Show me proof it sells more, not a brochure."
Fair enough. Two recent field studies, run in real grocery stores and measured on real receipts, give her that proof. They also explain why a screen does what a poster can't.
(Rachel is a composite character. The research is real and linked.)
Scene 1: Promo week, the poster way
It's Thursday. Head office has confirmed next week's deals: two-for-one on a snack brand, and a price cut on cooking oil. Rachel emails the artwork to a print shop and waits.
On Monday the posters arrive. Her assistant tapes one to the snack end cap, props a standee near the entrance and slides discount tags into the shelf rails beside the oil, which sits in the back aisle.
By Friday the snacks are moving. The oil barely is. Rachel suspects most shoppers never walk far enough to see the tag. Moving the message means another print run, another two days and another bin of paper. So the posters stay put, saying the same thing at 9am on Monday as at 7pm on Saturday.
Every campaign costs her about a week of lead time, a few hours of staff labour and a print bill. Once a poster is up, it's frozen.
What's hard about this
- A printed sign only works if shoppers walk right past it
- It never changes, so the eye learns to skip it
- Days between a decision and a sign on the wall
- Mistakes need a reprint, or a marker and an apology
- No easy way to fix what isn't working mid-campaign
Scene 2: Same promo week, with screens
Same Thursday, same deals. This time Rachel opens her content manager, drops in the artwork and builds a short playlist: the snack deal, the oil price cut and a store-hours reminder. She schedules it for Monday on the screen at the entrance and the one above the main aisle.
She leaves the discount tag on the oil shelf. The screen plants the idea early; the tag closes it when the shopper arrives. That pairing is exactly what Nanni and Ordanini (2024) tested across two supermarket experiments with over 7,000 shoppers. Discounts shown on screens lifted spending on products located far from the screen by 22–30%. Their explanation is simple: moving images catch the eye in a way print doesn't, so by the time shoppers reach the aisle, they've already seen the offer, and the shelf tag reminds them.
On Saturday evening, when the store is busiest, Rachel lets the snack video play more often. That instinct has backing too. In Herhausen, de Jong and Grewal (2026), which tracked 237 campaigns across ten grocery stores, seeing a screen ad made shoppers 8.1% more likely to buy the featured product. The lift was strongest for indulgent, lower-priced products, on weekends, later in the day and when stores were crowded.
When a slide has a typo, she fixes it from her phone in under a minute.
It's not magic. Someone still decides what goes on the screen. But the gap between noticing something and changing it shrinks from days to minutes, and the message reaches shoppers before they reach the shelf.
Side by side
| Posters and standees | Screens | |
|---|---|---|
| Time to launch a promo | Several days for printing | Minutes |
| Fixing a mistake | Reprint, or a marker | Edit from a phone |
| What shoppers see | The same image all day | Moving content that changes by the hour |
| Reach | Only shoppers who pass the sign | Points shoppers to products elsewhere in the store |
| Mid-campaign changes | Rarely worth the cost | Swap a slide whenever it's not working |
| Waste | Paper and foam board every campaign | None |
What does NOT change
Screens aren't a magic switch, and the same two studies say so.
- The shelf still matters. The screen and the shelf tag work as a pair.
- Screens don't sell what's right beside them. Nanni and Ordanini saw almost no lift for nearby products. A screen's job is to send shoppers somewhere.
- Clutter cancels out. Herhausen and colleagues found the effect weakened when other promotions competed for attention at the same time.
- The message matters. A bigger discount didn't produce a bigger lift. What's shown, when and where counts more.
Rachel still decides which deals are worth pushing, knows her regulars and reads the room on a busy Saturday. The screen gives her a sign that moves. She gives it a message worth showing.
Behind the scenes
A cloud-based content manager connects all your screens to one dashboard. You upload artwork once, arrange it into playlists and set when each one plays. Changes go out to every screen right away, from wherever you are.
Try it in your store
Cloudy is built for exactly this: content everywhere, managed from anywhere. If you want to try the screen-first, shelf-second approach contact us today.