Facebook gives full detail on all the data it is collecting and using to sell ads

The site admits that it tracks people as they use the internet and then lets advertisers use that information

(AFP/Getty)

Facebook has attempted to clarify the full amount of data that it collects on its users.

In a post titled 'Hard Questions: What Information Do Facebook Advertisers Know About Me?' the scandal-hit site details everything it collects and attempts to explain why it does it.

The full scale of that data has been laid clear in recent weeks as the company has been attacked for the vast amount of information it collects on its users.

In a new post, it promises that it is not compromising people's privacy in the way that it collects data about them. And it aggressively attacks the common suggestion that Facebook's users are its product, writing that it simply uses its ads to make sure it can keep that free.

It explains that it gathers information to use for ads in three main ways. First it watches how people use Facebook, so that if they like a page about bikes they will see ad for bikes; second, advertisers can bring information to Facebook, allowing them to target people who have already bought their products, for instance.

But the final one is almost certain to be the most controversial. The site admits that it watches how people use the apps and websites they visit and then use that to work out which ads to show to them.

By doing that, it can target people who looked at a certain kind of show on a totally separate website, for instance, or focus on people who added that shoe to their cart but didn't finish actually buying it.

Facebook continues to argue that it needs to collect all of that information to make the experience of using it more enjoyable. "For example, we can show you photos from your closest friends at the top of your News Feed, or show you articles about issues that matter most to you, or suggest groups that you might want to join," it writes.

It says the same applies to marketing, allowing it to show "better and more relevant ads". It suggests that it allows independent coffee shops to survive and that collecting data helps benefit people raising money for diabetes.