Good question.  Ask it; there are many many approaches among the
     people on the newsgroup.  From cohousing to communal living to
     group marriage to things-undreamed, there are a multitude of
     ways.  Design a new one and see how it works. Unlearn assumptions
     about an old arrangement. Ask questions, and practice empathy.

     Most of all, polyamory seems to be about building new
     configurations of relationships rather than trading people in and
     out like baseball cards. As amanda r. clark says:

	 "Poly is being open to the opportunity if it comes along, not
	 refusing commitments because something better might come
	 loping down the path."