General George Armstrong Custer was not a general.
At least, not when he died.
Custer, commanding the United States Seventh Cavalry, had enjoyed the rank and privileges of Brigadier General during the War Between the States. But this was a "brevet" rank -- a temporary appointment during time of conflict.
Following the end of the war in 1865, Custer was returned to his "nominal" rank of Lieutenant Colonel. And it was as Lieutenant Colonel he met his end at the battle of the Little Big Horn.
Prior to the battle, Custer made one crucial mistake. (Actually, he made quite a number of mistakes, but only one of them could be considered crucial.)
He underestimated his enemy.
Disregarding reports from his native scouts, Custer was of the opinion he could easily defeat the Indian tribes arrayed against him. After all, he had done it before. In fact, Custer had gained quite a reputation as an Indian fighter.
Unfortunately, he believed his own press.
And this bred overconfidence.
Custer further weakened his command by dividing it into three separated columns. He planned to strike his enemy from different directions in an action he envisioned as a great victory.
Meanwhile, Chief Sitting Bull had a different vision in mind.
Where Custer divided his command, Sitting Bull concentrated his mounted warriors. Sitting Bull had also committed sufficient resources to carry the day so that he outnumbered Custer's troops many times over. And while Custer chose to ignore his scouts (read: consultants), Sitting Bull wisely listened to his scouts' reports.
Sitting Bull attacked Custer's three columns in turn, inflicting a stunning defeat on the troopers and ultimately annihilating Custer's column, of which only one cavalry horse survived. The detached columns under Major Reno and Captain Benteen were unable to come to Custer's aid (they were fighting for their own survival).
Custer might have won the battle of the Little Big Horn if he could only have convinced Sitting Bull to send his forces to battle one warrior at a time.
In advertising, we often fail to concentrate our resources. By dominating a media, the competition can be overwhelmed. Indeed, concentrating a media budget can actually overcome a competitor with a much larger budget spread over many days or many media.
The concept of concentration can be illustrated by sitting in a lawn chair under a summer sun. One can remain in the sun's rays for many minutes with no ill effects. This is because the sun's rays are diffused over a wide area.
But position a magnifying glass so those same rays are focused on your arm and you can't stand more than a second of the concentrated beams!
The lesson learned from Custer (and Sitting Bull) is concentrate enough resources to dominate your chosen media and outwit your competition.
And never underestimate your opponent.