One definition of a hook is a musical or lyrical phrase that stands out and is easily remembered. Definitions typically include some of the following: that a hook is repetitive, attention-grabbing, memorable, easy to dance to, and has commercial potential and lyrics. A hook has been defined as a part of a song, sometimes the title or key lyric line, that keeps recurring.
Creative accounting is a euphemism referring to accounting practices that may follow the letter of the rules of standard accounting practices, but deviate from the spirit of those rules.
The creative concept is essentially the story behind the messages presented in an ad or series of ads. It ties together the characters and elements in advertisements to help convey a memorable and effective message that will create the desired behavioral response from the target market.