"So What" became Pink's most successful single from Funhouse (2008). In the United States, the song entered at number nine on the Billboard Hot 100 in the issue dated September 6, 2008, earning the highest debut title for that week. Two weeks later, the song topped the US Hot Digital Songs chart, selling 197,000 digital downloads. One week later, in the issue September 27, 2008, it topped the Billboard Hot 100, selling 253,000 downloads that week. The song became her second number-one hit on the chart after her 2001 collaboration single "Lady Marmalade" with Christina Aguilera, Lil' Kim, and Mýa. The song also topped the US Adult Pop Songs in the issue dated December 20, 2008, and on the US Pop Songs chart for four weeks.Sources for "So What" positions on the US Pop Songs Chart (Billboard):
