What was the purpose of the gladiators in Ancient Rome?

It seems like every culture needs a hero to worship.  In Ancient Rome, gladiators filled the role of hero in much the same way that professional athletes are revered in American society.  The gladiator games were the ancient equivalent to the modern-day Super Bowl.  Romans attended the events by the droves.  While the "major leagues" of gladiator games were played in the Coliseum in Rome, there were smaller venues throughout the empire.  Gladiators had to earn their way through the smaller games to reach the Coliseum.  The purpose of the games was  for entertainment for the masses.  Emperors used the gladiators to keep the citizens happy, particularly the lower class plebians.  It can also be said the gladiator games kept the plebians distracted.  In times of crisis, the emperor would host gladiator games to improve the general mood of the city.