Complex sentence: "Little Things" had sold 502,000 copies in the United States by 7 January 2013 and was certified gold by the Recording Industry Association of America (RIAA) on 23 January 2013, denoting sales of 500,000 copies.
Split into simpler sentences: Little Things had sold 502,000 copies in the United States by 7 January 2013. The single was certified gold by the Recording Industry Association of America (RIAA) on 23 January 2013, denoting shipments of 500,000 copies.