In a few simple reports, you can determine the effectiveness of your content. Effectiveness has been defined as 'revenue generating' and this presentation uses Google Analytics reports.
16. 50%According to Slate.com, 50% of people didn’t
scroll down the page.
http://www.slate.com/articles/technology/technology/2013/06/h
ow_people_read_online_why_you_won_t_finish_this_article.html