When you approach a venue for a gig, they ask, "how many people can you bring?" Some follow that up with, "we don't have a built-in crowd here". Usually even a small venue wants you to bring 20 people, which is dang near impossible for someone just starting out, and just beginning to build a fan base. But how can you get fans if you can't get gigs? It's a chicken and egg dilemna.
I was talking to Dan, my drummer, about this recently. He reminded me that, in the past, clubs had a built-in crowd, and people went to the same one or two clubs/bars all the time, regardless of who was playing. I remember that era. I remember I had a few places I liked to go, where bands played original music, and always enjoyed the thrill of hearing a good band (or singer-songwriter) who I had never heard of before. I still do this.
So what happened? How did we get from the venues with built-in crowds to venues where you have to bring your own crowd? Another negative with this is that, how can you reach new people if you always play for the same people you bring? I guess you can reach the fans of the other band playing, but that's it.
Of course, the other side of this is, with a built-in crowd, the band (or singer-songwriter) has to get a reaction. As Dan said, you had to be *good* to be invited back. Without a built-in crowd, whether or not you're invited back has nothing to do with how good you are, it's how many people you bring.