Bill Barnwell ran a column over at ESPN.com about last Weeks Super Bowl - and Kyle Shanahan decision to take the ball first. Which was a bad idea. Bill Barnwell article mentioned percentages and analytics of taking the ball first or kicking off.
However, he missed one big point. If you kick off you can't lose the game.
The offense can punt, kick a field goal or score a touchdown on that first possession - but the team that kicks off does not lose. However, the team that kicks off can actually win the game on the first drive. They could get a safety (unlikely), a fumble return for a touchdown or even an interception return for a touchdown. (Or even if the fumble return or interception does not give you a score it can give you great field position.
If you kick off and the other team scores a TD with an extra point - then you know you have to score a touchdown (and you will always be playing four downs). If you score that touchdown and you almost always wants to go for the 2 points. Because it is better to have the ball at the 2 yard line to win as opposed to tying the score - having to kick off and stopping the other team from scoring and then you having to march down the field again to score
If you lose the coin toss and the other team elects to kick off - the team that gets the ball first can turn the tables by scoring a TD and getting the 2 pt, and they then know that when they kick off THEY CAN'T LOSE THE GAME.