You've got your music. But that will only carry you so far.
The real multiplier for your music career's success is the velocity of your fans. Do they rabidly promote your band because they connect with you and love what you stand for? (As much as I dislike them, you can't deny the efficacy of Juggalos for supporting their band.) Or do the people you've touched actively go out of their way to discourage others from listening to your music?
It used to be that there was an invisible wall between the artist and their fans. PR spokesmen, artist managers, burly security guards, tinted limos etc. If you didn't want to talk to the public beyond your music, you would have someone step in for you and create a buffer. You could live in space when you weren't on stage as far as anyone was concerned. Rest assured there was someone out there actively interacting with fans, spreading the gospel of your music.
But the middlemen are disappearing.
Today it's just you and the fan. They can interact with you directly through twitter, myspace, forums, email, carrier pigeon... If they see you before or after a show, they wanna talk to you. The fan *expects* to be able to interact with you. This is part of your job description as an artist. Communicating emotion involves communication.
Why is this?
Choosing to listen to a band is an identity decision.
When I say "I'm a HUGE fan of Boris", it's an identity statement. Music is all about emotions, philosophy, and stories. When we state our preferences, we're explicitly saying "I identify with the message they are conveying to the world. This band and their music represents how I see the world." We project the person we want to be onto our artists.
As such, we as your fans want to know as much as we can about who we have decided is worthy of membership into our "Personal Identity Club". This is a club for cool people *only*, because we're the president of it!
So if we finally interact with an idol and they look down on us, blow us off, or call us chumps, they're out of our club. Gone. Even worse, any time the former-fan hears the artists name, they're gonna chime in saying "They're a dick! Don't listen to em!".
Even not replying to their messages is a slight. If you don't respond to fans' attempt to connect with you, to them it feels the same as a gorgeous woman who won't return their calls. It hurts.
You can't ignore or hate on your fans anymore. They're the only ones keeping you afloat.
Know your fan velocity. Do everything in your humanly power to maximize it.