[whatthemick]

I'm interested in this aswell. I assumed "Show HN" was the appropriate thing since you clearly state it's a type of self-promotion.

I personally appreciate people being upfront about it being promotional, StrongLoops latest "tutorials" have been a bit of a sinner in this regard. They usually provide great content but always mention their own services (which is fine in my opinion but it should be obvious from the get-go).

Edit: Perhaps the prefix is removed to remove any bias, perhaps people are inclined to be more positive towards user contributions - Perhaps by removing Show HN you let the product live on its own merit, rather than any type of emotional bias.

[jevin]

That sounds like a good reason. Maybe someone can confirm this?