answer:As an ad copywriter, I learned to write sentences in short bursts, and often, starting one with “So” was both necessary and effective. However, I don’t do much of that kind of writing anymore and now tend write complete sentence for the kind of materials I do write. On the spoken side, everybody at my office but especially engineers starts sentences with “So,” and I dislike it, not just because it sounds like the “in” thing to do, but more importantly, because it’s rarely necessary. For example, why start a meeting with the sentence, “Today we’ll be discussing such-in-such” with ‘So’? I just don’t get that.