I think the data points can be congregated not necessarily into one continuous profile knowing that you've been on website X, website Y, and website Z, but if website X is a finance website, it's very possible that there may be an indication that the browser has visited a finance website. If the next one is on a travel website, there's a possibility at least that a cookie indicating a preference for travel would be dropped on the browser subsequent to that.
On December 11th, 2012. See this statement in context.