As Pariser points out, personalization is endemic and ubiquitous:
When you search for the flight, Kayak places a cookie on your computer -- a small file that's basically like putting a sticky note on your forehead saying "Tell me about cheap bicoastal fares." Kayak can then sell that piece of data to a company like Acxiom or its rival Blue-Kai, which auctions it off to the company with the highest bid -- in this case, probably a major airline like United. Once it knows what kind of trip you're interested in, United can show you ads for relevant flights -- not just on Kayak's site, but on literally almost any Web site you visit across the Internet. This whole process -- from the collection of your data to the sale to United -- takes under a second.
Why is this something you should worry about?
Well, it's not terribly easy to explain, but Pariser tries, presenting several interesting perspectives on why there are downsides to having your computers conform too subserviently to your desires.
Firstly, there is the fact that "some of the most important creative breakthroughs are spurred by the introduction of the entirely random ideas that filters are designed to rule out":
in moments of major change, when our whole way of looking at the world shifts and recalibrates, serendipity is often at work. "Blind discovery is a necessary condition for scientific revolution," they write, for a simple reason: The Einsteins and Copernicuses and Pasteurs of the world often have no idea what they're looking for. The biggest breakthroughs are sometimes the ones that we least expect.
Another important reason is that it's not clear who "we" are, since human beings don't have a simple, easily classified identity:
The personality traits that serve us well when we're at dinner with our family might get in the way when we're in a dispute with a passenger on the train or trying to finish a report at work. The plasticity of the self allows for social situations that would be impossible or intolerable if we always behaved exactly the same way.
Personalization doesn't capture the balance between your work self and your play self, and it can also mess with the tension between your aspirational and your current self. How we behave is a balancing act between our future and our present selves. In the future we want to be fit, but in the present, we want the candy bar. In the future, we want to be a well-rounded, well-informed intellectual virtuoso, but right now we want to watch Jersey Shore
Pariser is not claiming that he can solve these problems; at this point, all he really wants to do is to raise awareness about what is going on:
We live in an increasingly algorithmic society, where our public functions, from police databases to energy grids to schools, run on code. We need to recognize that societal values about justice, freedom, and opportunity are embedded in how code is written and what it solves for. Once we understand that, we can begin to figure out which variables we care about and imagine how we might solve for something different.
Pariser's book covers a number of important issues of the moment. This is not to say it's a perfect book, unfortunately. Like all too many popular non-fiction books, it stretches out the page count with wordy text and filler; I felt like this was a great 30-page essay that became a 200 page book. Pariser is a skilled writer and the book reads well; you'll move through it in a few days. And you'll learn a lot and you'll look at the Internet with a new eye, so these are good outcomes and good reasons to spend your time with this book.