Complex sentence: "Party Rock Anthem" also reached the top five in Italy and Norway, and was the third best-selling digital single of 2011 with sales of 9.7 million copies worldwide; it is also LMFAO's biggest throughout their career.
Split into simpler sentences: Party Rock Anthem also reached the top five in Italy and Norway. Worldwide, "Party Rock Anthem" was the third best-selling digital single of 2011 with sales of 9.7 million copies; it is also LMFAO's biggest throughout their career.