With one billion users, more than half of whom log in every day, it's no surprise to anyone that Facebook generates massive amounts of data. The numbers are too big to have any relevance, it's hard to put them in context.
The fact that it's the largest photo site on the planet is well known, it's not even a competition, actually.
People upload some 300 million photos every day to the site, three billion every ten days. There are hundreds of billions of photos stored by Facebook. Flickr boasted last year about the sixth billionth photo
uploaded to the site. It may have added another billion or two in the meantime.
Any given hour, Facebook deals with some 105 terabytes of data. 2.5 billion pieces of content, 500 terabytes worth go through the site every day.