I would also use the ellipsis a bit at the end of a post, sometimes instead of pointing out the glaringly obvious, other times to imply my wonderment at a poster's lack of cop on, basically to avoid insulting them outright.
For example, if a poster (and there are a lot who can't figure things logically) asks;
'I got a watertight written quotation from a reputable builder with excellent references to build my house for E50/ft2. Is this good value?'
(I'm exaggerating here to make my point) I would reply with;
'What do you think yourself...?'
This to me is better than saying 'Take an hour to ring around other builders for quotes, find out the prices of materials, do a couple of simple sums and you'll very quickly figure out that it is of course good value, you lazy dumbass.'
The ellipsis is much more civil and polite.