Free apps actually making money

More proof that free, ad-supported apps can actually make bank by being totally disruptive:

In short, they’re responding to Google Apps and Google Docs, which now account, according to analysts, for up to 2-3% of Google’s total revenue (call it $400m a year, up from $40m a year ago) (note: I can’t find a source for this, but it was quoted to me by a senior Google employee last week). That’s still pennies compared to Microsoft’s $16b or so in annual Office revenue, but the trend is pretty clear - users like free, and they like the ability to collaborate on documents. Today, Google offers what is in many ways a superior product to Office and they don’t charge users for it.

Is it any surprise then that the three biggest online mail services make up over 6% of all internet visits in the U.S.?