Abstract
Medical journal websites frequently contain tracking code that transfers data about journal readers to third parties. These data give drug, device, and other medical product companies a potentially powerful resource for targeting advertisements and other marketing materials to journal readers based on unique attributes and medical interests that can be inferred from the articles they read. Thus, while editors may strictly regulate the content of advertisements that such companies place in their journals' pages, they simultaneously provide those companies with the means to target readers in other forums, possibly in ways that subvert editorial guidelines. We examine the implications of third-party tracking on medical journal webpages, and recommend actions that publishers, editors, and academic societies can take to curb it.