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.

Question: What did ABBA do after winning?
Self-contained rewrite: What did ABBA do after winning the 1974 Eurovision Song Contest?