I’ve got a comments system on here now. Do I reply in there to a comment, or do I post for the world at large?

Is there some kinda ruling for this? Some de facto standard I should be following (and which I’ll ignore anyway as I hate the term ‘de facto’ almost as much as I hate the fact I always imagine it being said with hand-signalled quotation marks).
Just curious.

Ohh crap, what do I do if someone posts an answer in the comments….