Everyone, theres no need for your local shop to accept BTC. All they need is cash. Cash simply works and its faster.
The idea of encouraging them to accept bitcoins is just another option for them and they can even do something new about it. We know that most of them are just accepting cash but this type of acceptance for their payments is somehow unique though the thing is that you just need to explain to them what bitcoin is and possibility to create another investment with it.
It can be an option for them but what use will it be for them? Will it be worth it for them to hold BTC with all the volatility, the recently regular high mem pool size and the hassle to convert back to fiat? Are the local shops' customers BTC holders? If only adding another option is your reason, why not encourage them to accept US dollars or gold as well? Those are good options too.