Conversation so far:
What was ABBA and the Eurovision song contest?
Ulvaeus, Andersson and Stig Anderson believed in the possibilities of using the Eurovision Song Contest as a way to make the music business aware of them as songwriters.
Did ABBA win the Eurovision song contest?
ABBA won the 1974 Eurovision Song Contest on 6 April 1974.
What was the song that ABBA contributed?
ABBA sung Waterloo in English instead of their native tongue.
What did ABBA do after winning the 1974 Eurovision Song Contest?
Winning gave ABBA the chance to tour Europe and perform on major television shows; thus the band saw the Waterloo single chart in many European countries.

Question: Did the appearance help boost album sales in the U.S. market?
Self-contained rewrite: Did ABBA's appearance in the United States help boost album sales in the U.S. market?