Sorry this isn't about inches.     :)
This is about the audience.
Today I wanted to share a little bit about what the live experience is like for a singer/songwriter. 
The audience is what it's all about.  Each song has to be sold every time you sing it, every show is an audition.  The audience decides if I'm worth sticking around for.  There are of course unknown variables.  Will I screw a song up?  Always possible.  Will I beat myself up about it?  Not immediately but most likely later.  Probably the most important of all the variables is the kind of audience you're playing for.  What I mean by that is why are they there?  The type of venue you're playing has a whole lot to do with that. 
The bar scene: 
Well for the most part people are there to drink, talk and network (take that as you may).  The musician is merely background noise.  If you're lucky you can break through the chatter and carousing to win over some fans who will come back specifically to talk through your next show.  Fans who come to these shows to listen often express their frustration at how "rude" people are to talk through the show.  The truth is it's a bar.  That's what people do in bars.  When you've spent enough time playing in that environment you learn to not take it personally.  Does the audience matter?  Absolutely!  You start to build your fan base in these rooms.  Believe it or not there are people who will deal with the bar scene so they can hear/see an artist they really like.  At the end of it all it's still a bar.
The Listening room:
These rooms are set up to cater to folks who want to listen.  Every little nuance matters so you need to be on your game.  What's all too important is the energy that comes from the audience.  You feel it and it has a direct impact on what you give back in your performance.  This may sound kind of airy fairy but so true.
Any musician will tell you they've trudged through the experiences of playing to rooms that were virtually empty.  I remember years ago playing to two extremely drunk guys in a pub.  One of them was pretty close to passed out at his table.  That's it, two guys in the whole place.  So you know we always say that regardless of how many people are there you still give the same show.  That's true in theory, but playing in a room that feels really empty sucks the energy right out of you.
Playing to a room of people who really want to be there and feeling like you're connecting, now we're talking positive energy.  It literally injects life into your show and you relax, you share, you have fun and it's why I'm a singer/songwriter.