So What Have I Been up to?

Hi Fellow Etsians! It's a cold rainy day down here in Australia, and I'm sitting here shivering on my computer chair.

I've finally got into making BNR Treasuries. So, What is a BNR treasury? Good question. I still not quite sure, but I think I'm closer now! (Please comment and tell me what you think a BNR is)

So, for instance, I've been making these sorts of treasuries(visit these links):

http://www.etsy.com/treasury/NTY1MDc5M3w0NTg4NDk0MTk/open-bnr-purples-up-to-10
http://www.etsy.com/treasury/NTY1MDc5M3w0NTg3OTcxODU/open-bnr-reds-and-blues-1?index=1

BNR definitely means Buy and Replace.
So I think what is meant to happen is that someone buys something(for whatever price) and posts the transaction link after they've bought something.
Next the curator has to either replace the shop featured that someone has bought something from with an item from the buyer's shop.(If you follow me) But I'm not sure whether you are meant to make a completely new treasury or keep on with the old one. Could someone set me straight?

Cheers!
Elizabeth