This marketing tactic should be illegal. It's not even good because no one is going to be happy when they get there. Sure, getting people in the door is a win, but when they hate you it doesn't work as well. Then again, we all know that there's no such thing as free beer. What's bizarre is that you're more likely to get free beer if you're rich and can already afford beer. That's true of everything. Rich people get shit for free all the time.
Remember when punk bands would name themselves things like Free Beer and Nude Girls? That way no one could look them up. That's how anti-establishment they were. There's something cool to that, but by something I mean like 10%. It's 90% stupid. Help people listen to your music, ya dopes.