Fergie is set to make $4 million by promoting a US clothing firm in her songs.
The 32-year-old Black Eyed Peas singer, who has become the first star to agree to product placement in her songs, will write and perform tracks endorsing fashion company Candie's on her second solo album.
An executive at Fergie's record label Interscope said: "With record sales in decline, you must find novel ways to make money out of the music. The trick is to make the brand part of the song so that it slips down easily rather than chokes the fan.
"Candie's will have no say over exactly what Fergie will sing, or when. Fergie does not sing jingles so it will have to work unobtrusively in the song."
Fergie - real name Stacy Ann Ferguson - has also agreed to appear in Candie's TV adverts and allow Candie's advisors to style fans at her shows.