How the credit card companies make money?

I have the same type of free charge credit card with dividend about 1% yearly also, and I pay every statement on time, so I don't have to pay interest. In fact when I travel, I ensure to buy all my air tickets or transportation with my credit card and I get free travel and medical insurance protections (some good gold cards give your over 2 million dollars maximum medical protection (with special airplane return if needed), with less than $200 yearly fee for 27 days overseas travel or over, but you may allow to go back the same card when you return home. I love and enjoy the system so much but you must keep yourself in the best credit rating and should not even have more than one speeding ticket within certain months or years. On the other hand, credit card companies would like to serve good credit rating customers because the more they shop and use, the card companies get more percentage or service charges or commissions from retailers and so increase their returns or number of accounts. At last, their companies' stock prices go up, and they can sell the whole credit card accounts or divisions to new investors--this is why they keep sending new cards out and spending  lots of advertising in different channels to reach mass populations as much as possible. Credit card companies ' major marketing strategy is: Sales is just a numbers game.