You get a llt of regulars sometimes, and sometimes they're really cool, sometimes they're really annoying. I've had regulars invite me to parties before, ask me if I want to go out with friends, etc. I work in a busy discount retail chain, so we serve the greater community surrounding us. Many of the local, regulars know each other.
I do the same thing I do with coworkers. I don't date them. All it does is cause drama. I'll make quasi friends with them, but I'm working in a semi-professional (casual pro) environment. I'm there to do my job, not socialize with patrons. I can socialize, and thats part of a decent customer service experience, but I have work to do.
I keep it short, professional, but also personal. I know several customers on a first name basis, and go out of my way to help them should they need it. However, this same service is also rendered to other customers whom I don't know on a first name basis.
I do my job. Some customers are awesome, regulars are super cool, everyone gets treated the same. I have had some customers give me their contact information. Some fine ass Latinas.