AS SOUTH Korean popster Psy soars towards an unprecedented 1 billion YouTube views for his giggle-inducing Gangnam Style, the cash registers are ringing even though he gives his song away free. Viewing the YouTube clip is free, and potentially copyright-infringing parodies are adding tens of millions to the global giveaway of his song. Yet Psy has earned an estimated $US8.1 million ($7.7million) from people seeing value in the global phenomenon. The song has topped charts in more than 30 countries including Australia, Germany, Russia, China, Spain and Britain. In Australia it is still in the top 10, selling almost half a million copies since it entered the charts three months ago. Its sales top 3 million in the US, more than 300,000 in Canada and 600,000 in Britain. In Psy's native South Korea, downloads are approaching 4 million. Most of Psy's newfound wealth comes from TV commercials for electronics companies and car manufacturers. Another chunk comprises his slice of the revenue from ads that accompany the YouTube video. Some even comes from Gangnam Style parodies. As The New York Times explains, it works like this: YouTube automatically detects Gangnam parodies, then asks users to delete their video or share their ad revenue. Most choose the latter, and YouTube gives some of this to Psy. In the passage to super stardom, Psy has shown a reluctance to enforce punitive copyright measures for misuse of his song, ignoring a tactic frequently employed by other big acts. For example, more than a decade ago, the heavy metal band Metallica sued file-sharing site Napster for copyright infringement. Understandably, it did not approve of potential paying customers downloading its songs free. However, in Psy's case his song became a word-of-mouth smash first, which attracted the media's interest, which helped further cement its international success. And while Napster rang the bell for massive changes in the record industry, Psy's Gangnam Style adventure shows musical megastars are not relying on retail sales alone to make a fortune. Peripheral earnings can be just as lucrative, or better. Not to mention world domination, Gangnam Style.