The reason certain users or companies 'break through' to me on HN (i.e. achieve a long term identity in my brain) is because they change my model of how the world works.<p>Two examples -- Posterous and Mixergy. Mixergy has gotten lots of visibility on HN lately, Posterous maybe not quite as much (though maybe I just haven't paid as much attention to Posterous lately). But both changed my model of the world in some way. Posterous, for making me think more about email as the least-common-denominator social network publishing platform, and the value of tapping into that, and the technical issues involved with doing so; Mixergy, for the content of the interviews, but also for the <i>format</i> -- I think a Mixergy-style site on ambitious young neuroscientists could be really interesting, and good for my field as a whole.<p>Posterous and Mixergy changed how I think about things, and because of that, I'll probably remember both for as long as I live.<p>This is a different model of brand awareness from the one that is implicit in the poll results linked to here -- that brand awareness is some function of the number of times a brand gets posted per unit time and the popularity of the post. For me, that's just <i>visibility</i> -- but <i>stickyness</i> comes down to, "Did this change my model of the world?"<p>And that's the value I get from the better posts on HN, the better New Yorker articles, etc.