As an American Maiden fan, I will also discuss my disappointment at my own country's poor music taste. And I believe Forostar nailed it, followed by even The Drifter's post. The US seems to be more into pop these last several years, followed closely by all these horrid boybands and girlbands (quoting Bruce, "WHO CAN'T EVEN FUCKING PLAY!" haha), who are so popular thanks to all the little teeny-boppers.
While I don't know what the coasts are like, as I am near St Louis, Missouri, I will say that our main radio station KSHE95 (they call themselves "Real Rock Radio") NEVER plays Iron Maiden. And I mean NEVER. You will never hear an Iron Maiden song on the radio here, much to my disappointment. Yet you hear bands like Metallica, ACDC, Judas Priest, Ozzy, etc... ALL THE TIME! And I'm not saying anything bad in regards to those bands... but if they are played, then why not Iron Maiden too? I won a contest about a year ago and got to tour the KSHE95 studio and have lunch with all the DJ's, and I discussed with them about Iron Maiden, and to my surprise not a single one of them seemed to care much for the band.
I guess heavy metal is just taboo in the US nowadays. Which is really shameful. But please do not associate the idea that "US don't like Maiden". I'm sure there are tons of Iron Maiden fans here in the US, especially these past few years with Flight 666 releasing, and the spectacular Somewhere Back In Time tour, and soon coming up El Vivo concert.
That being said, the last two times I've seen Maiden (both in Chicago, 2008 Somewhere Back in Time and 2010 Final Frontier tours), the places were full and the crowd was wild (more so during the SBIT tour than the FF tour... I'm assuming just because it was classics compared to new material. While I love it all, I'm sure I am the minority unfortunately). And both times Bruce said that Chicago was one of the best US cities. I'd sure believe it, I was hard of hearing after the SBIT concert, the crowd's cheering was deafening between songs.
Iron Maiden is my favorite band. Has been for the last 4-5 years, and will probably remain so forever. But unfortunately the US just has kind of poor taste in music, I guess.