The credit card industry started doing the same thing the car industry did to get new customer by offering 0 interest rate credit cards. That let to a lot of costumer shopping around to get 0 interest rate credit cards.
We used to be happy with just getting a good rate and maybe a little kickback once a year, now we are assailed with offers of zero interest from every direction and it sounds like a really good deal, but is it really? Are the companies really giving you a zero interest loan of their money?
Credit card companies look at the zero interest offer as a way to get you to come on board as a client, the expense of the zero interest offer is simply a cost of doing business for them.