Measuring Global Patterns of Internet Use

The revolution in digital and mobile information that is sweeping around the globe has market research firms racing to measure changing patterns of media use.  One of these firms, globalwebindex, came to my attention in an alert this morning.    They have published some interesting data based on survey research in major markets around the world.  One of their surveys, in June of 2011, produced the accompanying graphic, which plots a measure of engagement with e-commerce (based on whether a respondent purchased a product online in the past month) against a measure of social engagement (an aggregate score of "Manage a social network," "write a blog," "comment in a forum," "upload a video," and "microblog.")
A glance at the nice graphic (click to see a full size version) shows unsurprisingly that Korea is the world leader in e-commerce (note the dark pink circle for South Korea is highest in the chart).   However, South Korea ranks lower than quite a number of countries on the measure of social engagement.  This would seem to be partly an artifact of the measure itself and cultural patterns in Korea.   A closer look at this question would require access to the full data and information on how the measure was operationalized.   However, on the face of it, I'm surprised to see South Korea ranking anywhere but near the top on a measure of social engagement.