Considering that Facebook has multi-billion dollar valuation, makes money selling users advertising, and makes money selling analyses of user information, my view is that the users are kindly donating Facebook their information, not that Facebook is kindly donating their service. While users may benefit personally from the service being available, Facebook are the ones benefiting financially.

Users do not give Facebook money directly, but they contribute something valuable to the company just by using the site. I see it as a business relationship the same as if I was paying money for the service.