Conversation so far:
who does the song i can only imagine
I Can Only Imagine is a song by Christian rock band MercyMe.
is there a movie called I Can Only Imagine“
I Can Only Imagine is a 2018 American Christian drama film directed by the Erwin Brothers and written by Alex Cramer, Jon Erwin, and Brent McCorkle
Is the movie I Can Only Imagine based on the song by Mercy Me
The film I Can Only Imagine is based on the story behind the group MercyMe's song I Can Only Imagine, the best-selling Christian single of all time.

Question: how many copies did the song sell
Self-contained rewrite: how many copies did the mercyme song I Can Only Imagine sell