simple here are the reasons per priority\n\n1- There is no commercial break.  Teams have to play 45 mins without interruption and this would only allow for commercials during half time.  The US is learning that there are other ways to commercialize this sport by having brands sponsor the team shirts and by having logo placements around the field. (Red Bull has even purchased the MLS team in NY and changed the name to the NY Red Bulls, very smart move) (you also have Chivas USA, lets not forget).  So this is becoming better and the sport will grow even more.\n\n2- The US has a lot of other sports: Baseball, Football, Golf, Hockey, etc... It hard to push one more sport to the market.\n\n3- There aren't a lot of points scored so you need a history of rivalry to make it exciting, the sport in the US is not there yet as the teams need a more impact history!!!  \n\nHope this helps