The following report is courtesy of Miriam Datskovsky from Portfolio.com:

In the big, bad game of rock and roll, 'Stairway To Heaven' is undeniably a winner. Released by LED ZEPPELIN in 1971, the eight-minute song is considered a musical masterpiece and is one of the most-played rock tunes of all time. Proving its longevity, 'Stairway' hit the UK charts again last fall and was a top download in the US, after Zeppelin’s first downloadable album launched on iTunes. But because the band is notoriously protective of its work, 'Stairway' hasn’t met its full moneymaking potential. While other artists have made big bucks by licensing songs to Hollywood and Madison Avenue—think of BOB DYLAN’s 'Love Sick' in that Victoria’s Secret commercial—Zeppelin has shunned most opportunities. We consulted executives in the music, advertising, and entertainment industries to come up with some numbers, real and potential, for the value of 'Stairway'.

Zeppelin hasn’t licensed 'Stairway' for movies or commercials. But songwriters Jimmy Page and Robert Plant and Warner/Chappell, the song’s publisher, make money off royalties from record sales, radio plays, and live performances. Zeppelin has played “Stairway” at every gig since 1971, yielding about $150,000 in royalties. Everyone from Frank Zappa to the London Philharmonic has also performed it, and let’s not forget the hundreds of thousands of proms, weddings, and bar mitzvahs where it’s been played. (D.J.’s and venues pay a small annual fee for the right to play it.) Estimated gain: $400,000. Royalties from album and DVD sales total about $8.6 million. Plus 'Stairway' has been played on the radio an estimated 2,985,000 times (equal to more than 45 years of uninterrupted airtime), netting nearly $2 million. It’s also thought to be the bestselling piece of sheet music in rock history, with royalties of $1 million.

Read more here.