"Gangnam Style Link Spurs DI Surge" http://www.bloomberg.com/news/2012-10-17/-gangnam-style-link...
"How Much Did It Cost YouTube To Stream Gangnam Style?" http://www.forbes.com/sites/quora/2012/10/29/how-much-did-it...
Psy only made $32,000 USD from domestic online sales of “Gangnam Style”? http://www.allkpop.com/2012/10/psy-only-made-32000-usd-from-...
Make sure you read that article, those are Domestic (Korean) sales where prices are a lot lower. This is partly because songs in Korea are so much cheaper than other songs to download. At the cheapest, American songs are 791 KRW (approximately $0.71 USD), Canadian songs are 804 KRW (approximately $0.72 USD), and British songs are 1064 KRW (approximately $0.96 USD), but Korean songs on average are at 63 KRW (approximately $0.06 USD).
and
his other sales outside of domestic online sales combined are estimated to have reached 100 billion KRW (approximately $90 million USD).