Google Reader and KPI

I went back to Google Reader today and noticed some changes. While parsing my new RSS aggregated feed about web analytics, I stumbled on an "Instant Cognition" post wondering how Google Reader decides if a post have been read or not.

One of the first thing I did in the new Google Reader incarnation is to go under Settings/Preferences and uncheck "Scroll tracking", which is said to behave like this: "In expanded view, mark items as read when you scroll past them." However, experimenting with this features tell me it might be a good idea after all.

How to determine if a post was read?

Even if a post is in the current focus, nothing tells us the person is actually reading it. However, in expanded view, we should notice the framed color around an individual post changes as we scroll. A nice touch from Google to remind us of the post currently being in focus. I think the idea of "onFocus" + time could have some meaning, but "time" should be ajusted based on the post length.

Which KPI to use in this case?

• Ratio of focus time to post length (longer post/longer focus, shorter post/shorter focus, but ratio tells us how much attention was awarded to an indiviual post)
• Feed depth (out of X new posts, how many were read?)
• In this case, could the notion of "page view" be replaced by "post view"?

This always remind me of "The Attention Economy" by Davenport. We used to try to get attention to our sites, now we try to get attention to individual posts!