Thought this was pretty interesting, especially in how a West Marches campaign can deal with the problems of having more players interested in a game than you can accommodate at the table, and the dreaded specter of scheduling issues. Might try to run one myself at some point!
I don’t know how old it is, but it’s certainly not new. The article linked is one I read several years ago before I ran my own West Marches game.
Edit: the post is dated 2007.