Complex sentence: It was also a success in the United States, reaching number 3 on the US "Billboard" 200 chart, and although it scored on US charts for half a year, steady sales have resulted in its certification by the RIAA at 4x platinum.
Split into simpler sentences: It was also a success in the United States, reaching number 3 on the US "Billboard" 200 chart. It scored on US charts for half a year, and steady sales have resulted in its certification by the RIAA at 4x platinum.