Charles Duhigg has a fascinating and somewhat creepy article in the New York Times on how corporations can know so much about you through "predictive analytics." Target can figure out that your daughter is pregnant before you do, to take one example from the article, just from her series of ordinary-looking purchases.
Sellers have gotten so good at figuring out what you will buy and sending you suggestions when you are vulnerable to change buying habits that customers have figured out that they are being spied upon. So the companies have developed a new layer of subterfuge to hide their suggestions within seemingly random offers, most of which they know you will ignore.
The irony of my reading this article in the online version of the Times is that now the Times knows of my interest in predictive analytics, and can tuck that away in its own database of thing to try to sell me - such as Charles Duhigg's book on predictive analytics and habit formation.
I am reconciled to the fact that in exchange for the thousand ways that I benefit daily from the information revolution, the price I pay is that information providers know a great deal about me. And some of them will try to sell me stuff, based on that information.
I don't see "living off the grid" as in any way an attractive strategy. So the realistic options in a world in which large corporations and the state constantly spy on me are
1) live a public life; and
2) buy at small local stores. With cash.