I been saying this to clients for YEARS, but so many insist that price and promo works. Not that it doesn’t, but people just don’t respond to it like they used to. This is why a copywriter should be able to be versatile and be willing to push the limits a little in order to capture people’s attention. If it makes people laugh, they will share it with their friends and that brings way more weight and extra value to the advertising and marketing campaign.
You can find the link at Nielson.