When you are performing be sure to tell people specifically where you are going to be appearing. Be sure to list the city and state (country?) of where you are going to be. Preferably put the whole address, there are lots of "Main Streets" around the world.
Include a link to a map or a web site and tell the people who you want to come there why they should go out in the cold, rain and traffic (or why they should be inside on a nice day). Is it a bar? a cafe? Non-smoking? Free WiFi? If it's packed all the time tell them to come early and get a table. If it's always empty, tell them there is lots of space. Tell me there's free parking or that section of downtown isn't busy that time of night but it's safe in that area.
Get your fans motivated, tell them what time you're specifically going to be on. Someone might not want to be out all night but if someone knows you're on at 9 PM that might motivate them. If they just want to relax and not go out, but they see you're at a smoke free cafe with wireless internet it may entice them. I can't tell you the number of times I haven't gone out because I didn't know anything about the venue and didn't know what time the performance of who I wanted to see started.
If there are other performers that night, tell me about them too, give me a link to their site or a place where I can sample there music. Se if you can get the other performers to post the same information about you.