Matt Stoller has an interesting article on the history of credit rating agencies.

Two interesting tidbits, neither really the main point:

..in the 1960s, BankAmericard (now Visa), suffering from low adoption rates for its card, mailed millions of unsolicited credit cards to individuals. Not applications for credit cards, but the cards themselves. A crime wave ensued. Trucks full of cards were driven away by organized crime. People who received the cards didn't know how to use them. Many thought the cards were simply a way to get free stuff; they didn't realize they'd have to pay the bill later.

And:

As they say in the industry, with a credit card you can buy a car; without a credit card you can't even rent one. (I have a pet theory that the rise of credit cards in earnest is one reason for the dramatic drop in street crime since the 1990s.)