Sun Tzu said: 3. After crossing a river, you should get far away from it. 4. When an invading force crosses a river in its onward march, do not advance to meet it in mid-stream. It will be best to let half the army get across, and then deliver your attack.
In business: 3. After winning a profitable customer, you should make great efforts to retain him. 4. When a rival company makes price cuts to a customer, do not advance to meet it at once. It will be best to let it show its cards and then deliver your attack.