Though Twitter is one of the few companies that lets its users opt out of browser tracking, the social network is gearing up to deliver advertisements based on that very technology and more. Twitter says that it'll soon begin delivering sponsored tweets within the United States that are based on what its users do elsewhere on the web, such as where they frequent and what newsletters they subscribe to — a company could even promote tweets only to users who subscribe to their emails. Twitter hopes that users will find the targeted ads more useful than its standard sponsored tweets, which are usually delivered based on who a user follows within the social network.

The ads are new to Twitter, but they're far from new to the web. Facebook has been tracking users to deliver targeted advertisements for some time now, also combining information from its own network to make them even more specific. Because Twitter supports Do Not Track — a browser option that tells certain websites not to gather information on you — its users will be able to avoid those ads altogether if they choose. The ads will be enabled by default, but Twitter's willingness to consider user privacy has still earned it the Electronic Frontier Foundation's praises, even in light of the move. For now Twitter is calling ads an "experiment," likely as it gauges both the efficiency of the change, and how its users react.