The Internet research is mainly driven by data. Obtaining such data by planning and launching measurement campaigns is rather time consuming and costly. Much more efficient, and in many cases, sufficient data acquisition strategy is to exploit the existing datasets available in public databases, repositories, and documents. Hence, the public data sources related to the Internet usage and other Internet statistics are systematically surveyed and categorized to make the search for the Internet data much easier and faster. Extensive online searches and exploring websites of the key organizations were used to identify the data sources. Each data source was then carefully explored to describe its characteristics and contents. The data are usually aggregated over certain time periods and regions, and often indexed by age, gender, application, website, activity and other attributes. Some data sources also support various data visualization options, and offer data export in multiple formats
