Do you remember WYSIWYG? How about Videotext?
I’m showing my age here but does anyone remember the widespread use of the term WYSIWYG? It stands for “What You See Is What You Get” and it harkens back to a time before computers (any computers, including PCs) were able to show a reasonable image on the screen of what a document would look like (and yes the screens were generally black & white (or green). WYSIWYG was a major breakthrough and changed computing forever.
How about Videotext? This was a precursor to digital signage that distributed text newsletters, notices and bulletin boards to subscribers’ computers generally over slow dial-up modems. France had (and probably still has) the largest in the world with its PTT (Poste, Téléphone et Télécommunications) Minitel system.
So, you take WYSIWYG and Videotext, salt in about 20-30 years of technical innovations, and you get digital signage.