And someone doing that has certainly earned the right to include "one sentence that is the least salesy you can do" of self-promotion.
It’s quite amazing. I noticed these guys coming in the front page very often too, and while I agree their “hack” seems laudable while also not offending anyone (they’re doing what we are looking for), they seem to forget one more reason why they keep getting traction - the product they sell is absolutely on target to HN audience at an emotional level so people likely upvote due to that reason as well.