Cookies in the Wild

The results of an extensive survey conducted to determine the frequency of cookie usage, within modern web-based applications, is reported with a discussion of the current state of consideration of cookies within Web Engineering research. The survey indicates that cookie usage is approaching universal levels and hence there exists an associated need for relevant Web and Software Engineering processes, especially testing strategies which actively consider cookies; however, this requirement is at odds with much of the work produced by the academic community. A survey of 100,000 Internet sites, automated through the creation of a Firefox browser extension, demonstrates that over two-thirds of the sites surveyed utilize cookies, examinees the usage of first-party, third-party, sessional and persistent cookies within web applications. The survey identifies the presence of a P3P policy and the use of identifiable dynamic web technologies as major predictors of cookie usage. It is demonstrated that the usage of third-party persistent cookies is dominated by a small number of online marketing and web-tracking domains and a case-study and associated test-case is presented that highlights cookie usage within a single site and the need for comprehensive testing strategies for web applications that include cookies.