'Your benefit' means 'the benefit of advertisers, so we can now send you adverts that you want, because everyone loves adverts don't they?'
These Minority Report styled Facebook adverts will basically be tailored to you, based on where you are and what you're doing. As usual, this is all passed off with the line of 'enhancing your user experience'.
There are ways of trying to stop Facebook from tracking your activity. The obvious one is to stop using Facebook, but even then, some phones make it rather difficult for you to delete the app from your device at all, which is a fantastic pain in the hole.
One thing you can do, is to go through a third-party service, which again, is problematic, but worth a punt if you're determined to make Facebook's life a little bit more difficult.
In Europe, you can control how you're tracked online by signing up to YourOnlineChoices.com. where you'll "find information about how behavioural advertising works, further information about cookies and the steps you can take to protect your privacy on the internet." If you're in the United States of America, then you'll need to look at a similar thing called AboutAds.
In addition to this, go to your Facebook desktop site, and on the Home Page, click the arrow for the drop-down menu at the top-right corner of the page. In that menu, hit Settings and then, when the General Account Settings window shows up, click Ads from the left pane. From the right pane, you'll see the Ads Based On Your Use Of Websites Or Apps Off Facebook section - click the Opt Out link there. You'll be redirected to a web page, where you'll click the Opt out button.
Then, when the Confirm Opt out box pops up, hit the Submit button to confirm what you've done. You'll still see adverts on your Facebook page, but they'll be generic ads, rather than targeted ones, which is something at least.
We give Facebook 3 months before they work out a way around it and make us go through this faff again.