The article has this additional quote about Wikipedia - "Nobody can imagine this number. It's only when you see this in print or in a physical form that you realize how large it really is."
What is ironic is that when you get this in physical form it is really not that big. The following picture shows a range of books in a library. In this picture there are 771 volumes. Each volume is 1300 - 1500 pages. If we use the low end of the page range and take that times the number of volumes - 771 volumes X 1300 pages = 1,002,300 pages.
But to the scale of a library Wikipedia is not that huge.