Do companies only go green if it improves their bottom line?

It seems all the credit card companies are pushing for paperless statements which would cut down on the amount of paper that gets sent out monthly. Most try to persuade you to do this because it’s better for the environment and they get to save money too in postage, paper, etc. However for every paperless statement I’ve signed up for I still get 10 times the amount in junk mail from the same company. How are they really going green?