Walmart can't change their prices as fast; humans have to re-label things. For now.
Brick and mortar retailers can use radio-controlled e-ink shelf price tags for minute by minute price changes.[1] This hasn't really caught on yet, but the technology is ready.
Brick and mortar retailers can use radio-controlled e-ink shelf price tags for minute by minute price changes.[1] This hasn't really caught on yet, but the technology is ready.
[1] http://www.eink.com/esl_tags.html