MySpace has not only lost traffic, it is poised to lose revenue.

US unique visitor count traffic fell 8% between October 2008 and March 2009, to 70.1 million, according to comScore Media Metrix. Meanwhile, Facebook’s grew 33%, reaching 61.2 million.

Worldwide spending is expected to reach $520 million on MySpace in 2009, with $495 million coming from the US and $25 million from other markets. US spending on Facebook is expected to reach $230 million this year, for a total of $300 million in 2009.