Answer: Cause related marketing.
Explanation:
Cause related marketing is a form of marketing that is done by a profit motivated organization that seeks to increase the organizations profits and also better than the society through corporate social responsibility.
An example of cause-related marketing, occurs at checkout desks when customers are told to support a charitable cause by donating. Cause related marketing is a form of promotional campaign.
American Express donating 3 cents per transaction for a charitable cause is cause related marketing. The method will help increase it's customers and bring more revenue.