→ a comment to You call it privacy invasion, I don't [1] from Flameeyes.
What you state is a strong version of the “I’ve got nothing to hide” argument. If you’re interested in a thorough debunking, there is a very good article in the chronicle about that: Why Privacy Matters even if you have nothing to hide [2].
In short: It’s about an imbalance in knowledge. The danger is less 1984 (that only applies to the weak nothing to hide argument which assumes evildoing from others), but rather Kafkaesque: Other people take decisions about you without telling you how they reach those decisions. Since you do not know their sources (and often do not even know that they took a decision), you cannot correct misinformation about you. And the more those decisions from others affect you, the more you lose control over your life.
The good usecase for information would be that you explicitely request to get advertisements for certain types of wares. Or for wares which are similar to a list of wares you explicitely select. Then you know the data from which the others take decisions about you, and you can change it.
Links:
[1] http://blog.flameeyes.eu/2013/05/you-call-it-privacy-invasion-i-don-t
[2] http://chronicle.com/article/Why-Privacy-Matters-Even-if/127461/