This democratization of data is quite remarkable. A century ago the average person could create and access only a small amount of information. Now, ordinary people not only have access to huge amounts of data, but are also able to create gigabytes of data themselves and, potentially, publish it to the world via the Internet, if they choose to do so. Not only is digital information production the largest in total, it is also the most rapidly growing. While unique content on print and film are hardly growing at all, optical and digital magnetic storage shipments are doubling each year.
Digital information is inexpensive to copy and distribute, is searchable, and is malleable.
It goes without saying that the numbers in Table 1 can only be taken as rough estimates. We have had to make various assumptions in order to construct these figures, and some data sources are contradictory or simply not available. Here we list some of the most serious methodological qualifications, each of which offers interesting challenges for those who would seek to refine these estimates. A newspaper, for example, is published on paper, often published on the Web as well, and is generally archived on microfilm. Ideally, we would like to measure the storage required for the unique content in the newspaper, but it is very hard to measure that as a number.