Facebook has taken a rather surprising tactic with the launch of Facebook Questions – for now at least, the questions and answers on the service are not indexed on search engines. The content on Facebook Questions can only be viewed by logged-in Facebook users, making them invisible to the likes of Google and Bing.

A Facebook spokesperson told Search Engine Land: “Currently, search engines cannot access questions and answers through our Questions product. That may be something we consider for the future but have no current plans to allow it.”

It’s surprising because it reverses the trend of Facebook opening up more and more of its site to search engines over the years. Search engines are a significant source of traffic for similar services on other platforms – for example,  Yahoo! Answers derives more than 60% of its upstream traffic from Google, according to Experian Hitwise.

Questions and answers on Facebook Questions are visible to all 500 million Facebook users, not just a member’s individual circle of friends.