As of March 2015, "If U Seek Amy" has sold 1.3 million digital downloads in the United States according to Nielsen SoundScan.
9. maja 2009 je pesem zasedla devetnajsto mesto na lestvici "Billboard" Hot 100, s čimer je album "Circus" postal prvi album Britney Spears, katere trije singli so zasedli eno izmed prvih dvajsetih mest na tej lestvici od njenega prvenca "...Baby One More Time" (1999).