20 points in 58 minutes looks like it gets you on the top of HN, so as far as content marketing strategies "get your friends to upvote your HN submission" doesn't seem half bad.
* it's unfortunate that my reaction to seeing myself on hn is less "cool, readers!" and more "oh no, i'm about to get ripped apart in the comments"
I bet Reddit and HN use timing, browsing time, clicks, and mouse movements, among other things to tell if a lot of visitors are just coming to the site to upvote a single story or are genuinely browsing the site before coming across something interesting.
Of course that's what all anti-SEO people would say. Hmm.