As one of the "Big Four" music entertainment in Sierra (the others being the Polygon Records, Universal Music Group, and Warner Music Group), O.P. Entertainment is one of the largest corporations in the Kingdom with reported revenue of $4.725 billion in 2015. It is represented by the Sierran Music Forum organization in Sierra and the Recording Industry Association of America in the United States and Imperial States. In 2014, RBS Business named O.P. Entertainment as Business of the Year, and O.P. Entertainment was listed as one of Sierra's most influential companies. The company expanded its operations with regional subsidiaries in the Imperial States, Korea, and United States in 2009. O.P. Entertainment's headquarters are based in Irvine, Orange, Sierra, and are slated to expand operations