FYI, there’s a way that you can have some code placed on your website that uses the “visited hyperlink” information in a browser, so that you can query the person coming to your site to see if they have already visited other competitor’s websites. For example, we could theoretically place some code that when someone comes to our site, we can see if they have been to a competitor’s site, to Google, Bing, etc, to help build a profile of the person, and better target advertising and content. By knowing where someone has been (i.e. a sports site, weather site, cooking site, or medical site), it’s easy to create an educated guess about someone’s age, gender and interests, and then use this to your advantage. Here’s a link to the article: A browser bug that reveals all the places people go online, finds research. http://www.bbc.co.uk/news/technology-11899092