Some companies (i.e. Apple, Google) spend their time and resources on making better products to sell to us. Other companies take the effort to devise new ways to sell ads to us and make money that way.
According to a recently discovered patent filed back in December 2010, Microsoft has devised a way to not only track a user’s online activity, but then also correspond an indexed emotional state to that behavior. Then, with a thorough database of emotional profiles, ads could be created to fit each and therefore be delivered to users while in those states. So, for instance, if you were feeling particularly sane and trustworthy one day, the system would send you Microsoft ads.
Obviously, this thing may never see the light of day so let's pray that's the case.