According to Wikipedia's count, the soundtrack for The Bodyguard is the third best selling album of all time. It sits among obvious contenders (Dark Side of the Moon, Thriller) and beats out the next closest soundtrack, Saturday Night Fever by 50% of that album's certified sales.

This seems weird at first. While the film was financially successfully, it was critically panned and has not endured in the popular memory at all. Other top selling soundtracks are from musically driven films (Saturday Night Fever, Grease, Purple Rain).

Now, the album did have "I Will Always Love You," the best-selling single of all time by a female artist. It won best album and the Grammy's, and two of its songs were nominated at the Oscars. Yet the other top albums don't seem to be driven by the success of their singles. Both the top digital and physical singles lists have little overlap with the albums lists. Most of the other artists in the top 20 albums don't even have any single on Wiki's list. Likewise, hundreds of albums and songs have received Oscar and Grammy noms without anything close to this scale of success.

We might compare it to the Titanic soundtrack. "My Heart Will Go On" sold nearly as well as Houston's single, and the film shoveled up Oscars and redefined "box office success." Yet The Bodyguard's claimed sales are still 50% greater.

Is it really just the strength of the single the sold this album? Was there extensive media/popular hype about the song? Was the album particularly promoted? Did it happen fall in some key point in the changes of music formatting and sales charts?