A think that there's a big difference between someone who is not part of your GLO buying a pin and buying a songbook.
I earned my pin because I learned what it meant. I earned it because I am an initiated member of Zeta Tau Alpha.
As for a history book, I just think that anyone can read up on the history of my organization. I actually find it flattering in a way that someone would pay money so that they could learn my organization's history and songs.
I don't see many people outside my GLO really wanting to buy a ZTA history book because they can find the ZTA history anywhere on the web. Also, the book, unlike a pin, can't be melted and then sold for something else.
