Interesting Visualization of Social Media

As reported on Mashable and elsewhere, TrendStream, who publishes the Global Web Index, has created an interesting visualization of the penetration of different social technologies in major markets around the globe. The data come from interviews with 32,000 Internet users in 16 countries. The PDF shows labeled pie charts with overlap. Displaying a grayed out 100% pie and then let each pie piece start at the same baseline is certainly a new way of allowing comparisons which are usually hard in pie charts if the differences are not obvious. The legend states that “The size of the arch’s, represents the audience volume in millions.” [Sentence unaltered from source.] The problem I see is that the thickness of the arches is different in order to improve display, but the thickness seems to represent quantity as well which is apparently not the case, or is it? The display implies two dimensions, angle of the arch and thickness of the arch, but the data is only one-dimensional.