From what I've observed, new comments are initially added as the first child of their parent and will stay there for a bit. They drop over time based on how many up votes they've received. I think there are other factors involved as well, such as karma as the commenter, but that's speculation.

Maybe read/click count is hackable (bots?) and there is plenty of motivation to taint the system (new products would love to make it to the top of HN). Humans up/down voting seems fairer, no?

You're absolutely right. I was thinking about that while posting my original comment. I wonder if you can ensure that "read/click" is only incremented if the appropriate cookie is present.

That, too, I'm assuming is hackable. Then again, up/down seems as hackable. I mean, the link click is just calling a handler:

<a id="up_13164626" onclick="return vote(event, this, &quot;up&quot;)" href="vote?id=13164626&amp;how=up&amp;auth=08cc6438787bda18f8904afcf50af38e31d34824&amp;goto=reply%3Fgoto%3Dthreads%3Fid%3Ddvdhnt%2313164626%26id%3D13164626#13164626"><div class="votearrow" title="upvote"></div></a>

Perhaps the auth attribute is a random CSRF token, while the end of the href appears to be this comments URL. It seems like we could use the same idea, hijacking the navigation event on the link itself, applying a CSRF/auth token, and incrementing the read/click count. Seems like this would basically be the kind of granular auth allowed by service like Google Docs.

Just spitballing.

Not sure how comments are sorted (bubbled up also by up-votes and reply count?) but I sure think they can be better layed out. I always get lost when threads grow big and it becomes hard to keep a mental map of the thread structure. Maybe expand/collapse the nodes could help.

I agree with you. Plus, I feel like I'm missing out on good sub-comments because the comments list itself has grown too big.