With paper printed books you have certain freedoms. You can acquire the book anonymously by paying cash which is the way I always buy books. I never use a credit card. I don't identify to any database when I buy books. Amazon takes away that freedom.
You'd think experienced political professionals would know better than to place their trust in exit polls notoriously inaccurate surveys that had John Kerry winning the 2004 election by five points when he actually lost by three.