Complex sentence: It was released on June 18,2002, and did not sell as well as its predecessor, "Infest", selling approximately 700,000 units, achieving gold certification in the U.S. It was certified Gold in the UK and Canada.
Split into simpler sentences: It was released on June 18,2002, and did not sell as well as its predecessor, "Infest". It still sold approximately 700,000 units and was certified Gold in U.S. It was also certified Gold in the UK and Canada.