I might have edited my comment as you submitted yours. I do recognize that is a point of failure. The only companies that know me in such a manner are Amazon,

I might have edited my comment as you submitted yours. I do recognize that is a point of failure. The only companies that know me in such a manner are Amazon, Facebook, and Google (Gmail and calendar, and I'm going to be changing that). Third parties could otherwise piece together what websites I visit to get a more in-depth picture of who I am more so that what Amazon can figure out from my purchase habits; Facebook can figure out from who my friends are, what I like, pictures I'm in, etc; and from what Google could by reading my e-mails or seeing the events in my calendar.