The Great Gig in the Sky is about fear of death, Us and them is about war, and I could be just guessing about this, but I think Any Colour You Like is about choice.
Every member has a total AZpoints number next to their name that represents how many AZpoints they have.
Although I suspect Roger was using the coin ironically for this song, it would be interesting to see a base player who used coins instead of picks.
Money, it's a gas.
I guess there are a few good reasons other than to just online.