Is this an American thing? Because I've never had my bank, my provider, my health care etc sell any of my data (at least as far as I know).
[1] http://www.spiegel.de/netzwelt/netzpolitik/datenschutz-vag-i...
Do you have a credit card, and have you read the pages of fine print?
To make myself clear, I'm not saying they don't do it. I'm saying it's probably illegal, therefore the fine print doesn't matter.