How might we measure the success of a music promo video?

There are many ways in which we can measure the success of the music promo video
. Downloads
. Sale figures
. Word of mouth
. How remembered it is
. Media coverage
. Amount of views on YouTube
. How influentual the song is
. Newspaper articles/Tv reports
. Charts
. Amount of publicity
. How many times it has been shown on Television
. VMA awards
. Most viewing of music videos are now online