Summary On the average Web page or blog post, users may read about 20 percent. The first 10 seconds are critical. This score supports your efforts in keeping readers longer.
Here is some very interesting work going on by my colleague Urs Gattiker in Switzerland who is working on algorithms to help businesses measure engagement on their websites.
This is tough work but I think Urs is on to something here. While we don't have measures yet on the quality of stories on a website/blog, the algorithms here will indicate if the stories you share on your site are captivating (longer site visits). If you end up with a low score, you probably need to revisit your content and visuals.
I look forward to hearing more about Urs' work as he continues to work on these algorithms and shares his results with us.