Knowledge is power, and data is knowledge

Major data analytics at work here. If you are going to play in the financial world, your data is going to be out there.

Doing this without full disclosure: Not so cool
Letting customers know before you do this: Well, I can't blame them for trying to not lose money

In recent months, American Express has gone far beyond simply checking your credit score and making sure you pay on time. The company has been looking at home prices in your area, the type of mortgage lender you’re using and whether small-business card customers work in an industry under siege. It has also been looking at how you spend your money, searching for patterns or similarities to other customers who have trouble paying their bills.

Thanks to Ron Lieber for the write up - http://www.nytimes.com/2009/01/31/your-money/credit-and-debit-cards/31money.html

Note: You might have to sign in to read the article. Go ahead and sign up, it's free and the NYT has some good material.