All fair points Graystoke4.
My own interest was sparked in the 80s on C4 when the 49ers and Cowboys were going at it and I still have the memories of seeing the players battle with the artic conditions during the stretch and play offs. Then there was a big gap until I put the telly on after a Sunday night shift when C4 started with it again in 2011 and I was hooked.
One of its appealing characteristics for me, and in comparison with footie in the UK/Europe, is the wage cap which means all 32 teams have the same, fixed budget to accommodate the combined salaries of all their players. So if they decide to splash the cash on the Quaterback they will have less money to fund the Offensive Line to protect him. Also wealthy owners are unable to do a Blackburn or a Man City. In a similar effort to keep things competitive, the worst team from last year gets the first pick of the new talent coming out of college.
Hence all 32 teams are in the same league effectively and stand a chance of making it to the Super Bowl at least theoretically (coaching, continuity and management also have an effect).
Ray