Facebook has donned its hard hat and done a spot of data mining, revealing some statistics about its Open Graph initiative, which allows users to share with their friends just what they are reading online.

At f8 back in September Facebook announced it had created a new type of app for media partners that would allow newspapers like the Guardian, the Independent and the New York Times to find out just what articles of theirs were being read by Facebook users.

According to Facebook, the Open Graph has been a success and results show the the Guardian's app now reaches four million monthly active users and many of them being from a demographic that the paper has found hard to reach – the 24 and under category.

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The Washington Post app has had 3.5 million active users and 83 per cent of those are under 35 years old.

Yahoo News and the Independent have also significant traffic increases – Yahoo by 600 per cent and The Independent garnering 1 million readers for its app.

When it comes to what has been the most read, it is the New York Times that has the most popular article – one which centres round before and after pictures of the Japanese earthquake and tsunami.

Speaking about the results, Andrew Miller, chief executive officer of Guardian Media Group, said: "As well as increasing traffic, the app is making our journalism visible to new audiences. Over half of the app's users are 24 and under - traditionally a very hard-to-reach demographic for news organisations.

"The Facebook app is one of a number of successful launches by the Guardian in recent months as our digital-first strategy gains momentum. We're delighted with the results."