This is something I dont understand; Why are we not using e-ink in signage more. E-readers are great gadgets - but there is a multi-billion dollar signage mark

This is something I dont understand; Why are we not using e-ink in signage more. E-readers are great gadgets - but there is a multi-billion dollar signage market that is waiting for disruption. Make e-ink screens in larger formats and use them all over the place. A hospital I recently worked on had over 1 million dollars worth of signage, static traditional signage, printed up. And they were struggling to find better ways to do signage and wayfinding. If we have e-ink panels that were easily integrated into structures and addressable (arduino wifi cards) we could really do some interesting things with signage. Let the tablet market takes its course, while e-ink fills in areas that tablets are too much.