The appearance of impropriety
Marketing is actually what other people are saying about you.
Like it or not, true or not, what other people say is what the public tends to believe. Hence an imperative to be intentional about how we're seen.
It may be true that the effluent from your factory is organic, biodegradable and not harmful to the river. But if it is brown and smelly and coming out of an open pipe, your neighbors might draw their own conclusions.
I know you washed your hands just before you walked into the examination room, but if you wash them again, right here in front of me, all doubts go away.
Yes, Ms. Congressperson, I know that lobbyist is your good friend, but perhaps someone else should host you on vacation.
Your brother-in-law may very well be the most qualified person on the planet to do this project for us, but perhaps (unfair as it might be) it would be better marketing to hire the second-most-qualified person instead.
Sneaking around is a bad strategy. You will get caught. Ironically, it's also a bad strategy to not sneak around but appear to be.
You will never keep people from talking. But you can take actions to influence the content of what they say.