The term: “butter fingers” is so well known, I think a play
on it would make for a fun ad for butter. So in this proposed ad for a brand of
butter, a couple would be preparing food in their kitchen when one of them
drops something on the floor, and the other one says: “Margarine fingers.” Then
the person who dropped the thing looks back at their partner and makes a ‘yuck’
expression, indicating that “margarine fingers” does not sound at all
appetizing. Then they decide together to use butter in the dish they are
preparing rather than margarine. Then the announcer says: “There’s just no
substitute for (whatever brand of) real butter.”