You must live in a very small town where locals actually know that. If you asked me where to make a copy in my neighborhood (much less city) I would have no idea.
Big stores don't really need much advertising - it's the small shops that need this, and it's exactly those smaller shops that would be less known to the locals.
I challenge the assumption that most of us wouldn't know where to make a copy in their neighbourhood, if such a service was available within a reasonable distance.
I live in Toronto, so not too small. I know my neighbourhood very well actually. If you bumped into me on the street I could tell you:
1) Where to make a copy (small independent office store nearby, but it's expensive, also where to find others).
2) Where to grab a coffee / baked goods with a recommendation of which one I prefer (none of them being Starbucks or a Tims).
3) Your options for Indian, Thai, Italian food, etc.
4) Grocery stores and the quality of their produce.
5) Local mechanics.
6) Parks.
7) Parking.
And plenty of more specific shops.
Most of these places are small independent shops. They really didn't need any signage since I've walked or driven past many of them multiple times.
I've only lived in this specific neighbourhood for a year and a half. I've lived in the city for about 15 years.
You may not know where to go to get a copy, but many of us do and not through any kind of superhuman effort either.
Also, having the internet on my phone means I can quickly find most services I need in a specific neighbourhood when I'm feeling too shy to ask.
There's no getting around the fact that socializing with the locals is inconvenient, but sometimes it can be a nice inconvenience.
It has the added benefit that if your business pisses off the locals (crappy service perhaps) they'll probably recommend a competitor if there is one.