John Kay, an economist at Oxford University, argues that advertising doesn’t work because of explicit messages. He suggests that one context is particularly important that of waste. By waste he means spending more on adverts than is necessary to functionally communicate the explicit message. That could be a 90-second ad, acres of white space on double-page spread or extravagant production values.
Advertising known to be expensive signals the volume of the resources available to the advertiser. As Kay says in his landmark paper:
The advertiser has either persuaded lots or people to buy his product already, a good sign, or has persuaded someone to lend him lots of money to finance the campaign.
Advertising works, not despite its perceived wastage, but because of it.