Sun Tzu was a 6th century BCE Chinese general, military strategist, and author of The Art of War. I did a Google search to find out who said, "keep your friends close and your enemies closer" and there he was.
I should warn you that I love Wikipedia and donate when they ask.
So, anyway, I'm skimming the page and decided that I had to share some of his nuggets. As you read them, think about how they apply to your daily sales situations. Enjoy!
What is essential in war is victory, not prolonged operations.
If you know your enemies and know yourself, you will not be imperiled in a hundred battles; if you do not know your enemies but do know yourself, you will win one and lose one; if you do not know your enemies nor yourself, you will be imperiled in every single battle.
To win one hundred victories in one hundred battles is not the acme of skill. To subdue the enemy without fighting is the acme of skill.
A clever fighter is one who not only wins, but excels in winning with ease.
If your opponent is temperamental, seek to irritate him. Pretend to be weak, that he may grow arrogant. If he is taking his ease, give him no rest. If his forces are united, separate them. If sovereign and subject are in accord, put division between them. Attack him where he is unprepared, appear where you are not expected.
Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win.
One defends when his strength is inadequate, he attacks when it is abundant.
All men can see these tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved.
A leader leads by example not by force.
If orders are not thoroughly understood, the general is to blame.
The general who advances without coveting fame and retreats without fearing disgrace, whose only thought is to protect his country and do good service for his sovereign, is the jewel of the kingdom.
OK, back to the 21st Century. Are you a good general?