While I agree with the general sentiment posted here, here's an anecdote from a famous publicist. He got in a taxi cab and in the conversation he told the driver what his profession was.
"oh well, that advertising thing never works for me" the driver said.
"what brand of cereal do you buy" - "Kellogs"
"what toothpaste do you use" - "Colgate"
"what's your favorite drink" - "Coca-Cola"