[ChrisNorstrom]

Yes. E-ink doesn't need electricity to show an image, it only uses small amounts of electricity to change the image. Technically, if it ran on batteries, you could pop in some batteries, change the advertisement image, and then take the batteries out and the image would stay like that permanently.

[VyseofArcadia]

Right, but how much does the display itself cost compared to $15 to print a poster out and stick it in a frame?

[outworlder]

$15 times the number of posters you want to rotate. Plus the labor to replace them, multiplied by the number that you have.

[floydnoel]

electricity isn't the only resource to consider, however