To make our ads relevant to you, Adzerk receives information about the page the ad will appear on. This information includes the subreddits used to generate that page (which may include your subscriptions), as well as your IP address from which your general location (your country or city area) can be inferred. Keep in mind that when you comment and interact with a sponsored headline, others who view that same ad may be able to infer basic information about the location of your computer (since some ads like for a music venue in San Francisco are only seen in some geographies). 