Here's a very well-written paper by Sebastian Chan (2008) that explores many of the issues that we discussed during the presentation:
http://www.archimuse.com/mw2008/papers/chan-metrics/chan-metrics.html

Some of the key topics explored in this paper: measuring success versus counting hits, the "rather nebulous concept of 'engagement,'" social media and the proliferation of our content beyond the context of our website.