At first glance, the comment wall on your page might seem a little confusing.
If someone leaves you a comment, there might be a tendency to write a comment straight back using the comment block at the foot of the comment wall. However, if you do this, the comment is left on your own wall and not that of the person who's left you a comment and by you doing so, the person you wanted to see your comment might not actually notice that you have responded (I hope you're understanding this?).
Maintaining the comment thread
If you wish to reply to a comment that comes into your wall, look for the set of links below to the comment (as illustrated in the above image). You will see a 'comment back' and a 'view thread' link - these are only visible to the two people involved in the comment transaction.
By commenting back, you'll leave your message on the other person's comment wall and they'll get an email with a link to the comment (unless they've un-subscribed) to inform them of the message.
Once a conversation starts to develop, a thread of the conversation is recorded; by clicking on the 'view thread' link, it is possible to follow all of the comments on one page without having to click back and forth to each other's comment wall.
Note that the comments are public and can be seen by the whole site so if you wish to take the exchange private you'll have to click on the 'send message' option.
The comment thread are only visible to the two people involved in the conversation.