American singer Ke$ha's debut release "Tik Tok" was the biggest-selling digital single in the world last year. It sold 12.8 million copies – three million more than Lady Gaga's "Poker Face", which topped the chart in 2009.
The Independent — American singer Ke$ha's debut release "Tik Tok" was the biggest-selling digital single in the world last year. It sold 12.8 million copies – three million more than Lad... more info