Mars has written some of the most successful pop and R&B hits of the 2000's, but not just for himself. His most recognisable is probably 'F*** You' (often seen as Forget You) by CeeLo Green. The catchy pop number peaked at number 2 in the Billboard Hot 100 chart and was the biggest selling single of 2011 in the US, selling 1,865,000 copies. Another successful number of his, which he is featured on providing vocals and guitar, is Travie McCoy's 'Billionaire'. The song peaked at number 4 on the Billboard chart and in July 2011, it had been downloaded 3 million times, becoming Mars' third song to do so. He also wrote Flo Rida's 'Right Round,' which can be heard on The Hangover soundtrack and he also co-wrote and featured on B.O.B's 'Nothin' On You'. Amazingly, he did all this before his own solo career even took off!
