Appeal to flattery[1] is a fallacy in which a person uses flattery, excessive compliments, in an attempt to appeal to their audience's vanity to win support for their side.[2] It is also known as apple polishing, wheel greasing, brown nosing, appeal to pride, appeal to vanity or argumentum ad superbiam.[3] The appeal to flattery is a specific kind of appeal to emotion.[4]
Flattery is often used to hide the true intent of an idea or proposal. Praise offers a momentary personal distraction that can often weaken judgment. Moreover, it is usually a cunning form of appeal to consequences, since the audience is subject to be flattered as long as they comply with the flatterer.[3]
Examples:
"Surely a man as smart as you can see this is a brilliant proposal." (failing to accept the proposal is a tacit admission of stupidity)
"Is there a strong man here who could carry this for me?" (a failure to demonstrate physical strength implies weakness)
A refusal which does not deny the compliment could be formulated thus: "I may be [positive attribute], but that doesn't mean that I will [perform action] for you."
It is not necessarily a logical fallacy, however, when the compliment is sincere, and directly related to the argument. Example:[3]
"You are a stunningly beautiful girl – you should become a model."