Shop window display screens that make people stop

A shop window screen works when someone walking past can read it in the few seconds they give your window, and what they read gives them a reason to come in. That takes a screen bright enough to cope with daylight on the glass, and one message at a time in words big enough to read from the far side of the pavement. After that it's mostly about changing it often enough that the people who pass every day keep noticing it.

The window is working against you

A home TV looks lovely in a living room and pretty sad in a shop window. Sunlight comes through the glass and lands on the panel, and your offer turns into a grey rectangle with some faint writing on it. Displays sold for windows are far brighter than home TVs, and they're built to cope with direct sun and the heat that builds up behind glass. If your window catches the sun for a good part of the day, that's where the hardware money should go.

Reflections are the other problem. Before you fix anything to a wall, stand outside at a few different times of day and look at where the street reflects in the glass. Put the screen where those reflections aren't, with its middle at roughly eye height for someone on the pavement. Too high and people walk under it. Too low and the window display (or a sale rail someone parks in front of it) hides it.

Portrait suits most windows. It sits like a poster, it fits in the gap beside a mannequin or the door, and everyone already knows how to read a poster in a shop window. Every Casty player can run in portrait, set per screen, and you design the layouts at a portrait size so they fill it. The guide to choosing a player covers what each kind of screen needs.

One check before it goes up: a lit display right against the glass and facing the street can count as an advertisement that needs consent from your local council. The rules differ between England, Scotland, Wales and Northern Ireland, so ask your council's planning team first. It's a much easier question to ask before the brackets are on the wall.

Write for someone who's walking

Hardly anyone stands and studies a shop window. They glance at it from a few metres away, mid-stride, often with a phone in one hand, and that glance is what you're designing for.

• One idea per slide. "Knitwear half price this weekend" works. Six offers on one slide don't, because nobody on the move reads that far.
• Big words. If you can't read it from the kerb, make it bigger and cut words until it fits.
• Strong contrast, dark on light or light on dark. Thin fonts, and text laid over a busy photo, vanish in daylight.
• A price where you can. "Wool scarves £12" gives people a reason to come in. "Great deals inside" could be on any window in the street.

Movement catches the eye. A short clip of a product, or a slow change from one photo to the next, will pull a glance from someone who'd walk straight past a printed poster. Keep the words still, though, and leave each slide up long enough to read. Around eight to ten seconds a slide, with four or five slides in the loop, is a fair place to start. There's more on timing in how long each slide should stay on screen.

What to put on it

The most useful slide is usually the offer that's on right now, with its price. After that, think about what would make a passer-by curious enough to step inside, such as new stock that's just landed or a late opening this week. Seasonal stuff goes a long way too (school uniform in August, gift ideas from November) as long as it comes down when the season's over.

In the Casty demo, Northgate Store in York runs its weekly offers on a portrait window screen, with was and now prices and a panel for the autumn sale. The prices sit in a dataset, so changing one is a quick edit to a row and the layout picks it up without anyone opening the design. Handy, because a wrong price in the window is the one every passer-by sees.

The window keeps working after you lock up. People still walk down a high street in the evening, on the way out for dinner or home from the station, and some of them will come back tomorrow if you give them a reason. Schedule a layout for after closing with your opening hours, what's on tomorrow and your web address. If the display supports power control from the CMS, it can switch off later in the night (ask us and we'll set that up). Saving energy with screen operating hours goes into that properly.

Change it often enough that regulars notice

People who pass your shop every day stop seeing a window that never changes, and a screen is no different. The difference is that changing a screen takes a few minutes and no printing.

Let the schedule do the changing. Each event in Casty has a start, an end and a repeat, so you can put next week's offers in today, set them to start at opening time on Monday and stop on Sunday evening, and get on with running the shop. Dayparts let one screen show different things at different times of day: a convenience store might show a meal deal over lunch and something for the evening from four o'clock. Each screen also has a default layout that plays whenever nothing else is scheduled, so a gap in the schedule never leaves the window blank. Scheduling weekly offers in a shop walks through a routine for this.

Set expiry dates on images and offers too, so last week's sale drops out on its own. An offer that ended a fortnight ago tells everyone walking past that nobody's minding the window.

More than one shop

With several branches, give every window screen the same tag (window, say) and make a dynamic display group from that tag. Schedule the offers to the group once and they go to every window. When you open another branch and tag its window screen the same way, it joins the group and picks up the offers without anyone touching the schedule. The weekly offers tutorial sets this up step by step using the Northgate demo.

Common window screen mistakes

A few habits turn a decent window screen into one people ignore:

• Too much text. If it takes longer to read than to walk past, it won't get read.
• A huge logo. People know whose window they're looking at, so use the space for the reason to come in.
• Sound. Nobody outside hears it through the glass, and your staff hear it all day.
• An untidy back. The back of the screen faces into the shop, so tidy the cables, or pick a display with the player built in so there's no box hanging off it. The supported devices page lists those.