On June 20, 2001, the Latin pop inspired "Ain't it Funny" was released as the third single from "J.Lo". It was originally written for the soundtrack of "The Wedding Planner", a film Lopez starred in. However, Adam Shankman, the director, chose not to include it in the film because it had too much Latin influence, and "Love Don't Cost a Thing" was used instead. Although "Ain't it Funny" did not chart on the Hot 100, it was a success worldwide, reaching the top ten in multiple countries, including the United Kingdom where it peaked at number three. It was her second consecutive single to reach number three there, after "Play". The song was used as background music in three television advertisements in Japan to promote the 2001 Subaru Legacy for a special campaign which was known as "Three Keys Legacy". Lopez herself was also featured in all three ads.