Conversation so far:
who wrote don't judge a book by its cover
The phrase is attributed to a 1944 edition of the African journal American Speech: “You can't judge a book by its binding.“
who popularized the saying don't judge a book by its cover
It was popularized when it appeared in the 1946 mystery Murder in the Glass Room by Lester Fuller and Edwin Rolfe: “You can never tell a book by its cover.”
who popularized the saying to butter someone up
Many claim this phrase has its origins in ancient India, when people used to lob little balls of ghee butter at the statues of various gods.

Question: what does the saying mean
Self-contained rewrite: what does to butter someone up mean