Which product earns the most money: free website, free iOS app, free iPhone app?

Which product earns the most money: free website, free iOS app, free iPhone app?

Added (1). Mark Zuckerberg has made lots of money by making a free website, the Facebook. But I also heard that making free iOS apps and free iPhone apps can also make lots of money. The top grossing iOS apps each make $500,000 per day. So which product earns the most money out of these products?

So you are comparing one of the top companies in the world like Facebook? Yeah maybe I'll be leading scorer in the NBA, I "heard" they make alot of money too.