StationOne

” While time spent on site is a strong proxy for engagement, and many marketers feel it’s an important qualitative measure, it can’t be effectively used to price ad inventory in a way that’s comparable across media entities.

As interactive media continue to evolve, so will the metrics used to assess its effectiveness. Until then, marketers must settle for buying online media based on quantitative metrics that use multiple factors that are only directionally accurate. Time on site can be a reasonable proxy for engagement and, thus, is a valuable addition to an online marketers’ tool set. ”

Check out the full article from ClickZ HERE

As a company, we don’t necessarily agree. Reason being that sites such as Hulu and Facebook have great user involvement and a great time on site. Sites with dedicated pages for Video and consequently video episodes can be tracked (Google Flash Analytics), and simply put: the longer a user watches a video, the more benefit for the Ad buyer buying the Ad spot on the page and inside the video itself.