here are three advantages (of the feature i have been referring to (not necessarily of that particular software at the 'football' site though it exhibits similarity only, UBB and it predecessor provided this feature much more robustly):
here's the thing: COMMUNICATION IS EVERYTHING.
when having conversations that go on day and night via an online forum:
1. one MUST be able to READ, 'before' entering the thread, WHO has responded and WHAT is their SUBJECT line;
2. people conversing may actually reply via subject line alone via the thread index, i.e., without the reader having to enter thread.
(this happens frequently -- entering some trivial keystroke in the body (to appease submittal) which is already opened and just underneath subject text box ; frequently signaling the reader that nothing further follows with Ø or NM, NT, or NF ending the indexed subject line -- that used to be automatic if no body was entered. this is efficiency and is less makes takes effort thereby making communications far more efficient, just compare to what has to be executed by the user now to read, write, post, and reply.)
3. this makes communications powerfully efficient and more intuitive, far easier for new users to grasp and thereby "attraction" to communicate is better initiated.
(gotta run, thanks very much.)