American raising the price of a checked bag to $40, other airlines have gone up to $35: American Airlines Raises Checked-Bag Fees – WSJ
How long do you think it will be before all airlines begin charging for carry-on luggage too?
Their goal is to force more consumers into either purchasing a higher fare class that includes checked bags, or in to having an airline credit card (which can cost from $100 per year and up, but may include credits if you spend enough money on the card each year).