"Their plans, if implemented, would represent not only a technological feat—tying people's Internet lives with shopping activities—but also an erosion of the idea of anonymity on the Web. It's an effort by the two companies to profit by selling access to the insights they gather about people with every credit-card transaction."
The full article can be found at: http://online.wsj.com/article/SB10001424052970204002304576627030651339352.html