Ghostwriting has a long and distinguished history, with some of the world's most renowned artists, authors, and politicians using ghostwriters to gain fame and money and influence the public. Ghostwriting has been shown to be effective and continues to benefit both people engaged in the process. Stars who have used or do use ghostwriters include Stephen King, J.K. Rowling, and Andy Warhol. All three are famous for their bestselling novels, which were not written by themselves but instead by other people. King admitted in an interview that he uses up to five hundred dollars worth of writing paper per month. Rowling said in a BBC interview that she also uses a ghostwriter, and that she has two sessions with them every week. The writer she works with is chosen by her editor at Pottermore, where Rowling posts updates about her upcoming books. Warner Bros. owns the Harry Potter film series, so they get first choice on any new material from Rowling and can pass it on to her if they don't want it. Warhol was a popular artist who worked in many different media including painting, pop art, and film. He created many pieces of art that weren't done by himself but instead by others. For example, one of his paintings is called "Thirteen Little Paintings", and it took him thirteen hours to paint it.