OK, my favorite quote from Sun Tzu and the right summary for a marketing playbook in his "conclusion":http://www.sonshi.com/sun3.html
Generally in warfare:
If ten times the enemy's strength, surround them;
if five times, attack them;
if double, divide them;
if equal, be able to fight them;
if fewer, be able to evade them;
if weaker, be able to avoid them. ?