Mark C.
I see what you mean, I assumed the context was the friends of PaulNTA whom where coming around slowly, but that is not necessarily what he was asking in the OP. Its also truly said that context is essential to an answer. As for the last line, I should be clear that by sympathy I mean strictly "harmony of\or agreement in feeling, as between persons or on the part of one person with respect to another. " or "the harmony of feeling naturally existing between persons of like tastes or opinion or of congenial dispositions. " not pity (as it is used in the vulgar). To that end gaining sympathy (In terms of agreement and loyalty) is exactly what we're trying to foster for our Lord.
You're notes on the problems with communication over the internet are received wholeheartedly. In person you can say 'you idiot" and it can be endearing, but there is no such luxury online. Last week actually I was talking to someone on messenger who was tending to Old Earthism and he was becoming exceedingly hostile, but when I had him over for lunch a few days later much more progress could be made because I could easily abate his hostility.
You're right that if you have a 1:1 situation with lots of time there is no particular advantage to my suggestion or any particular disadvantage to you'rs (Though I would speculate that
's might end a great deal of those conversations abruptly for the degree it is prone to being misunderstood). I was thinking along the lines of a small group of people\friends where it would be difficult to get a grasp on a conversation if you where to lose it, so setting people up to ask you to talk till you're done would be a great advantage. Online the odds are that peoples apathy would leave the question unasked and thus a more hardliner approach would no doubt be in order (I haven't really used anything else online anyway, perhaps the occasional feint)
Ultimately, as you noted, it depends on the exact audience (By that I mean the people who are hearing what you have to say, even if its one) and you're circumstances of speaking to them.
Edit: I meant to note one of the more pernicious reasons talking about children may have a bad effect. Both up here and in the States there is a campaign against children. Public school teachers are free too and very often do try to hammer in that overpopulation and having kids is the root of all the problems in the world (I am not exaggerating, it was in full effect when I was in school in Arizona) There are, frighteningly enough, people who think that having more than one child is not only a bad thing in general, but bad for the kids who don't get as much attention or whatever. The long held anti-polygyny argument is an anti kid argument now too... What a world we've come too...
That doesn't have anything to do with this conversation in context, its more of a lament than anything.
) such questions are generally asked one-on-one in person, in which case my answer - from vocal emphasis to facial expression - reflects an understanding of the individual. Of primary importance to me is whether or not the individual asking the question has a Biblical mindset; everything else follows from that. 
