"Japan: No Bitcoin Tax, Thousands of Stores to Accept the Cryptocurrency"
article published July, 5, 2017
https://edgylabs.com/2017/07/05/japan-no-bitcoin-tax-stores-accept-cryptocurrency/"AirRegi is a widely used, tablet-based point-of-sale app in Japan. Currently, around 260,000 establishments, stores, and commercial facilities use this proprietary app to accept payments from their clients."
It makes sense that a transition to accept bitcoin would be underway for more US-based stores.
I think retailers do not yet have the need to use bitcoin because of the high price of Bitcoin. If those retailers appear in underdeveloped or developing countries, they probably will not accept Bitcoin