This is the fourth single off of her Circus album. This was supposed to be the fourth single off of her Blackout album back in 2007, however, it was canceled. It has been said that the song had to be released as a single at some point in the U.S. due to contractual reasons with the songwriters/producers.
It is an uptempo Electro/Pop track that doesn't stray too far from the other songs on Blackout. Lyrically, it isn't anything special, but the hook really gets stuck in your head and it's fun to dance to.
Watch the music video here (YouTube)