Twitter To Target Ads Based On Your Timeline [expect more of this] | Social Marketing Revolution | Scoop.it
From ht.ly - April 18, 2013 2:10 PM

Fast Company posted that Twitter will follow Facebook's lead and use the links you share and keywords you type to tighten their advertising sweater around you. 

Web 3.0 is going to be the intersection of predictive analytics with social shares so expect more of this kind of algorithmic tightening. Every now and again I try to toss in a search or a tweet that is totally rogue just to drive the profiling algorithms watching my every move a little crazy :).