B&R or BNR is a relatively new term I learnt from Etsy :) It stands for Buy & Replace.
Here's how it works...
The post-master lists the first (original, main) list of sellers in a forum (this one, for example). Other sellers/buyers can buy from this original list of sellers, anyone of them and list their transaction link (e.g receipt link) on the forum as proof of purchase.
The shop that has been bought will be knocked off and the buyer's shop will be listed on the main list. Anyone can purchase from the list and get their shop listed up on the list. Anyone who's been bought off can buy their way back in too.. as many times as you like.
It works as a symbiosis process .. Win-win situation.
I've been bought off... time to craft more, and lurk to buy my way back in on the list :D