well, when communicating on a forum we do not have the benefit of tone of voice or non-verbal cues to emphasize our meaning. tone of voice changes and conveys a completely different message even when saying the same words. sometimes it is not so much what we say but the manner in which we say it. I think emoticons are helpful in confirming one's intent online when stating things. Let me give you an example:

You have been most helpful in sharing your wisdom.

You have been most helpful in sharing your wisdom.

OR

You're a mess.

You're a mess.