I saw an interesting comment on this, by LaDeeGee Genelle Majied:
Here’s a little back story about this song… Thom Bell, the creative genius that he is, asked Dionne if she wanted to sing with the Spinners in this song. She didn’t care for the song and didn’t think it would be a hit. So Bell tore a dollar in half and they each signed their names on it, and he told her that if the song didn’t hit #1, he would return his half of the dollar and forget about recording it. Well, she recorded the song with the Spinners, and it hit #1. Dionne sent Bell her half of the dollar with an apology on it.
The song reached #1 on the Hot 100, #3 on the Adult Contemporary chart, and #2 on the Hot Soul Singles chart in 1974.