I have been asked, by an EdTech researcher called Jen Rhee, to share this graphic, which comes courtesy of Open-Site under a CC-BY-ND license, in order to solicit further comments. Aside from the pedantic tic that I had when reading "amount of books", the graphic is pretty interesting. Wikipedia gets 4 times as many page views as libraries receive visits (US?). Considering how easy it is to visit Wikipedia, as opposed to going to a library, I'd say libraries are doing pretty well there.
The other thing that occurred to me was that Wikipedia doesn't exist without those underlying publications. You know, the things that sit in libraries. It's often touted that Wikipedia will replace these traditional forms. At present, that cannot happen. Wikipedia disallows original research. All material on Wikipedia must be cited from a publication that has been through the traditional publication process.
Anyway, comments most welcome.