Actually, I asked more to learn about which Show HNs became successful. I was curious if I could detect any common differences the startups themselves that posted on HN in their infancy, as opposed to the total pool of startups or the total pool of Show HNs overall. (Of course, as someone pointed out, there's also the fact that startups who posted Show HNs are going to be much more likely to have gone through an incubator like Y Combinator. That may be a distinct enough difference that it washes out anything else about their initial product or submission. Still, I can't imagine EVERY success from Show HN was a result of subsequently doing Y Combinator...)

On a more selfish note, I also figured that people discussing this would cause me to learn about more interesting companies with ties to HN that I hadn't heard of before.