I just read trough the very insightful article "Defining Attention on Websites & Blogs" from Joseph Carrabis on iMedia Connection. We both share the same skepticisms about using "time" as the sole metric in the evaluation of "attention". Don't take me wrong, I'm not saying time isn't a useful element in the evaluation of attention, I'm raising a flag to the fact that both Compete.com, and now NetRatings are releasing reports where "time" seems to be the new golden metric, replacing the "page view". When we read "time spent is probably the best single indicator of user engagement" in the NetRatings report, I can't help but wonder what was their mindset when they wrote that.
When we look at the "time per visitor" results of NetRatings, most of the top sites share one characteristic: they facilitate the state of "flow". Flow was described by psychologist Csikszentmihalyi as being "the mental state of operation in which the person is fully immersed in what he or she is doing, characterized by a feeling of energized focus, full involvement, and success in the process of the activity"... and a distorted sense of time...
In the end, it will be up to web analysts and experts to educate their audience about the real value or misleading conclusions that can come out of the "time" metric. And the answer, as usual, is "it depends". But I still strongly feel than any analyst using only a "time" report to explain "attention" or "engagement" should be turned back to their desk and dig for a better story.