Quite so. As I said in the text, the distinctions between friendships and relationships don't really show up at the level of goodstuffodynamics (there must be a better word for it than that!), but in practice the way they work out for me is that some of the types of Good Stuff exchange that are specific to relationships work in such a way that they give me less Good Stuff when they're not done monogamously.
I have a Shiny Insight that mobbsy and me came up with about this sort of thing that I really must destruct-test against your attitudes some day :) In short I think there are different _ways_ of doing the kinds of Good Stuff exchange that happens in relationships and I'm not certain I was over-competent at the ones that don't leave other people drained..