Jae Jong (auntie Jong) has been making fried pork for many years. From 6 AM until closing at 4 PM, there is a line in front of the shop. Around noon time, the line is 3 times as long as in the picture taken at 8 AM.
The food shop next to that of Jae Jong makes "anything you want" (made-to-order). There are plenty of empty seats available at all times.
Jae Jong only does fried pork. Not fried chicken, beef or fish. She sells tens of kilos of it every day. She has a single shop and never opened any branch, although her reputation would undoubtedly make other branches successful. Her shop has no air-conditioning and hasn't changed for ages. She never innovated on her fried pork. There is only one kind of fried pork; no sugar-coated friend pork, no chill-dipped fried pork and no 'design-your-own' fried pork. There's only Jae Jong's fried pork.
Jae Jong has remained focused on making the best fried pork, believing that people would come and come back for it. And they do, standing in line in the sun and heat every day (the shop does not have a day off).
I see many entrepreneurs struggling with focus. It is very tempting to add something interesting onto your portfolio, if it brings an immediate opportunity (a new client !). It is hard to say no when you are in need of business. So one client asks something, and they think "Why not, I could do this and I can always refocus later on." And then another client comes up with something else again. Or they see or read something and think that this could be cool as a new product or service. Quickly, they become average at doing many things, rather than excellent in doing one thing. Very hard to get your focus back once you've given it up.
Staying focused works. Yes, it takes time. But people will come back for your product or service if they know yours is the best around.