Where do you comment?

Twitter, FriendFeed, and RSS sharing are swiftly ensconsing themselves as the primary modes of communicating interesting information among friends on the web. Though each has a unique role, there is a significant amount (>50%?) of redundancy between them when a user identifies an interesting piece of information. Currently we have great tools for what I believe are emerging as a distinct set of use cases, but we have some redundancy around sharing and commenting that hasn't sorted itself out yet.

The RSS reader is where users find the information they think would be useful to their friends. First, they comment on the initial blog post itself, which gets broadcast using a comment network like disqus or intensedebate. Then they elect to share it in Reader, adding a note. It shows up in your google reader friends' RSS readers as well. Friendfeed also picks this up and broadcasts it to your network there. Finally, you go on twitter and post a tinyurl to link to the article, which also gets picked up on friendfeed.

It can actually get much worse than that if you have mobile listeners, facebook, chatterous, etc.; I use the others because they constitute the main use cases: primary source, a reader of raw material, a streamer, and a broadcaster. The others (while plenty useful) simply rebroadcast broadcasts or stream less comprehensively or read in a more prepackaged or esoteric way. To put it another way, you can insert whatever brand name you prefer for commenting, reading, broadcasting, and streaming/recording.

So, here is my open question: What does it mean when you comment on an article on the article itself vs. in your RSS reader vs. Twittering about it vs. commenting on a share in FriendFeed? Does it depend on your networks for each - i.e. you think one story would appeal to a wider audience than another? Is it random? Would it change if (when?) everyone on Facebook used these tools every day?

For me, my RSS friends are the smallest group, my twitter friends a bit larger, and my friendfeed network are (ironically) usually people I don't know personally but follow because they find interesting items. I don't generally comment on friendfeed items unless it is in reply to a friendfeed comment someone else has made, mostly because I feel like it interacts with a very small audience. I only broadcast on Twitter if I think something is pithy, funny, if it is or pertinent to an individual I know (also ironic). I am trying to do better about commenting on blogs because I like it when people comment on mine, but I have a sense of writing it in stone, which I am loathe to do because I am never sure-sure. It isn't rational. Commenting on a share on an RSS? I haven't figured that out yet, so I generally don't do it.