hm. to be frank, i do it with some people--but not in the sense that they're 'friends' or that i know them in real life. There's just some folks in chat that, i dunno, i feel like i should add "sir" or "ma'am" when addressing them. Likewise, there are those doms that are way too laid back for me to do it, it just feels out of place. I'm guessing, from what i've read and what i've seen from my own reactions, if it comes naturally, it does. If it doesn't, it's either asked for or not.