Jessie J: "co-writing 'Party in the U.S.A.' paid my rent for 3 years"...

Apparently, Jessie J's biggest success in the States came from behind the scenes of 'Party in the U.S.A.' which she co-wrote alongside Dr. Luke and veteran songwriter Claude Kelly. She originally wrote it for herself but later gave it to Miley Cyrus. In a new interview with the UK edition of Glamour, she reveals the extent of how much she reaped the benefits off that one song.

“‘Party in the U.S.A.’ paid my rent for, like, three years. Actually it was longer than that. That’s where I get most of my money. I write songs. I’m a singer. I love doing endorsements and stuff, but that’s all added on” she says. A lot of artists that under-perform with their own records, make their real money through songwriting royalties. Without calling any names, why do you think some artists make small changes to a song they didn't write originally? It's actually pretty smart, but for the real songwriters, they stay paid.
 
Thoughts?