(Financial Times) -- Watch this space: advisers say that businesses will do themselves few favours if they cut staff off from using consumer tools such as Twitter, Facebook or LinkedIn

Facebook is testing adverts in its members' newsfeeds that are tied to their behaviour on other websites, bringing one of the web's most effective forms of advertising into the heart of its social network.

The experiment could turn into one of the company's most profitable forms of advertising, though it also risks stirring up fresh privacy concerns if users find it intrusive, according to analysts.

The move, announced in a blogpost on Tuesday, marks Facebook's latest attempt to find new ways for advertisers to tap the largest online audience. The approach, known as "retargeting", is based on a formula that has proved effective on the web, though it does little to draw on the social relevance that Facebook has long said sets its service apart.