How DOES advertising work then?

For adplanners and the like:

In the pre Christmas (holidays to you, Gareth) rush, you might have missed this major U-turn by the lovely folks at Millward Brown research (the people who brought you the "awareness index" a key metric that assumes that advertising achieves its effect primarily by impacting memory – awareness and recall). 

Suddenly – after years of dissing those like my chums at Brainjuicer – who dared to suggest that emotions were the key to advertising effectiveness, the folk we used to know as The Leamington Spa Gang have turned 180 degrees. Apparently, emotion is everything or pretty much everything.

Nice to have you aboard, chaps. Will you be dumping AI scores then?