Back in March, consumer advocate Ralph Nader delivered the inaugural address for the Center for the Study of Consumer Financial Services (CSCFS) at the Rochester Institute of Technology. Among other messages, Nader explained that he doesn't have a credit card, nor will he ever get one. Why?

Well, he offered several reasons. For starters, he objects to the invasion of privacy. He also reportedly believes that credit cards increase the price of the goods we buy. (I'm not convinced that's really true, but it is true that merchants who accept our plastic cards pay fees for doing so, and it's not unreasonable to expect that their prices will be designed to make up for that cost.)

He also criticized big banking companies, like Citigroup (NYSE:C) and Bank of America (NYSE:BAC), asserting that the bigger the bank, the less likely it is to provide loans to small businesses and the more likely it is to charge high fees and penalties. That may well be the case, but there are upsides to banks growing bigger, too -- at least theoretical ones. Bigger banks may be able to enjoy economies of scale and offer lower prices to consumers. Yes, I know that this won't always happen. But many investors were happy to note that when the Ameritrade and TD Waterhouse brokerages merged, becoming TD Ameritrade (NASDAQ:AMTD), the per-trade commission cost went down for many customers.

I also think that Mr. Nader is going a bit too far in avoiding credit cards altogether. Yes, they permit undisciplined consumers to use them to dig themselves deep into debt, but for those who pay off their bills each month, they offer many advantages, such as not having to carry much cash around and being able to more easily track their spending.

Learn more about credit cards in our Credit Center, which features some surprisingly interesting info about the credit card industry. Being smart about credit can potentially save you tens of thousands of dollars. You can also read about all things credit-related on our Credit Cards and Consumer Debt discussion board.

You might also be interested in our own Motley Fool credit card, which is so snazzy that it serves as a conversation piece.

And finally, remember that credit cards are big business and investors can profit from it. If the industry doesn't make you uneasy, check it out. Look into card-issuing companies such as MasterCard (NYSE:MA), Capital One (NYSE:COF), JPMorgan Chase (NYSE:JPM), and American Express (NYSE:AXP). Many currently sport high dividends and are likely to keep making money off credit cards in the years ahead.

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Bank of America and JPMorgan Chase are Motley Fool Income Investor picks. Take the newsletter dedicated to dividend payers for a 30-day free trial.

Longtime Fool contributor Selena Maranjian does not own shares of any companies mentioned in this article.