Retail promotions move quickly. This week's offer is replaced next week, and printed posters and shelf tickets are out of date almost as soon as they go up. Replacing them across several branches takes staff time better spent with customers.
Space is the other constraint. A showroom can display only part of a range, and a customer who cannot see the size, finish or model they want may leave without asking. On a busy Saturday staff cannot be with everyone.
Screens help when matched to the job: a window display bright enough for daylight, promotion screens that are easy to keep current and a touchscreen for browsing the full range. See digital advertising.