NG Courtesy, that's right. Check out my song, .:Wherever She Is FULL:. for starters please,
I can't help but think that courtesy in NG is almost non-existent. Hey, some people have commented back on my songs, I'm grateful for that. But then there's people who don't bother replying or checking out your stuff (I'm guilty of that, denying it would make me a hypocrit). I've been changing such a bad habit and commenting people back on their work when I can though. Being an artist is about giving and receiving: You check out their stuff, crit, and then they do the same thing for you.
So y'know, whenever someone takes their time to comment on your songs, return them the favor. It's always nice to see people responding back. It doesn't hurt anyone, and it's common courtesy ;D