A couple weeks ago, I did an analysis of TechCrunch by analyzing the data from its Facebook page: http://minimaxir.com/2012/10/questions-equals-reponses/

In that analysis, I found that month-over-month, response rate (in terms of average Likes and Comments on news stories) seem to be stable, and increasing. While an increase in pageviews may be caused by linkbait titles, if people are responding to articles more frequently, we can assume that they're "relevant", in this case.