I think it depends on the circumstances of the one-night stand. There are people who will get drunk and have a one-night stand with anything that moves. I don't think they have much chance of starting a successful relationship. But then there are people who meet someone who strikes their interest, they don't see any reason not to have sex right away, and things carry on from there... I've seen it happen. I don't think the second scenario is the ideal approach, but it's definitely possible... and, I'd wager, not that uncommon either.