Circus is Britney"s fifth No. 1 song overall and asserts the importance of Britney Spears in the global music market. Currently she holds three songs in the most important radio Top 40 charts, starting with the breakout hit Womanizer, then Circus and now the rapidly rising third single If You See Amy. Another highlight is this marks the first time Britney has scored back-to-back No. 1 singles on the radio chart.