It seems like in the past (pre-2010s) the differences between Top 40 stations used to be more pronounced. For example, when I vacationed in LA around 2005-2007 and listened to KIIS FM, it sounded almost like a different format than KMXV in KC, though both were CHRs (way more rhythmic product). Looking up the chart positions, I remember KMXV spinning pretty heavily for months the Rob Thomas song Someday in 2010(Rob Thomas | Biography, Music & News | Billboard) and 21 Guns (Green Day | Biography, Music & News | Billboard) 2009, even though both songs peaked at #30 on Mainstream Pop airplay, according to Billboard. They also used to wait until 7 p.m. to play rhythmic songs like Blame It (#2 on the charts in '09) and ignored a lot of rhythmic songs like I Wanna Love You by Akon and Hypnotized by Plies. In 2010, KCHZ overtook them in the market. Is there a reason why the differences were more pronounced back then?