Recently, Bryan Eisenberg, in GrokDotCom, wrote about major changes in how Nielsen/NetRatings evaluates sites:
..“Nielsen/NetRatings, in June will release what it calls “time-spent” data and stop issuing its rankings by page views. The New York company’s rival, ComScore Inc. said last month that it is emphasizing a measurement called “visits,” which takes into account the time people return to surf a Web site in a month.”
Time Spent could work as a metric if Nielsen would take the time spent by a visitormoving the cursor around in a browser tab (plus a couple of minutes for reading content) and divide it by the total time spent by the visitor since they turned on their computer and connected on the internet(today)
ie: Ad page 1 = 222 seconds spent on page, tab 2 = 75 seconds / 3860 =
Total time online = 64 minutes (or 64×60= 3860 seconds).
222/3860 = user engaged 5.75% of time in browser tab 1
Total time online = user engaged 1.94% of the time in browser 2
Here's a simple case of two tabs running in one browser and visitor is much more involved in tab 1 than tab 2. Does analytics naively support this calculation ? No. It's easy to do if you can get the time spent online that constitutes a computer session (not a visitor session). If, at work, your online all day, your dividing each window of your browser by the total time spent online (8 hours).
Anyway, Biznology also has a good writeup on the Time Spent metric.
