I used one of those. There was a narrow time window prior to the dial-up age when multple telcos considered something similar, but the investment required (especially terminals) was massive. It was a pretty neat universe. I last played with Minitel data when looking at (of all things) _dial-up_ set-top-boxes with a basic browser (it was an Alcatel thing, I think, that talked to a Minitel gateway to render content).
