I was just running some stats for SlideShare and realized that the ratio of creators (people who upload slideshows) to viewers (who visit SlideShare.net) is just south of 1%. This fits in well with what Bradley Horowitz’s Content Production Pyramid described, with some caveats.
First Bradley also talks about the synthesizers. I have yet to calculate those numbers for SlideShare. However, SlideShare is an active bookmarking community (we have 2.7 tags per slideshow), so those numbers are likely to be meaningful. But a lot of the synthesis is also happening on the web. As people link to and embed slideshows, they add metadata about those slides. Some of the metadata is captured on SlideShare (e.g., we links back to all the embds). But a lot of it cannot be captured easily.
Secondly, the number of viewers is probably an underestimation in an era of widgets. Slideshows are embedded all over the web. Each embed leads to more views which our system does not directly capture.