I also want to point out a master-level psychological ploy that Cena carried out, one that is usually reserved for high-level politicians. Listen to Cena's promo, he added a subtle good ol' southern boy to his accent, even his verbiage changed. It wasn't over the top, it came off like, "oh me, I grew up in the south, but then moved to Boston, but you can still hear I have a lil' southerner in me." It connects him to them, despite whether it's true or not.
He stops enunciating words. Drops the "g" off words ending in "-ing," it's tone things. I looked it up, and low and behold, this week's Raw came from Greenville, South Carolina. I think it's safe to say I nailed that.
This is a common political tactic to get the crowd on your side. Hillary Clinton got called out for it when she was running for president. It gives the masses a way of feeling a better direct connection with you when they talk and sound like you do. You're now one of them.
http://people.ischool.berkeley.edu/~nunberg/authenticity.html