The worst ad is the one you don't know is an ad. It will be presented as a definitive answer.

They are persuasion machines

The most powerful advertisement is a recommendation from a friend.

Has a friend ever brought some product up, completely out of the blue, and had you ready to buy it almost immediately? The biggest challenge traditional ads have is breaking down your defences. For friends, they're down by default. If someone is a friend, an ad doesn't have to be subtle or context sensitive, although it does help. Random suggestions from friends work.

A lot of people have friend-zoned AI and will be especially vulnerable to this novel form of manipulation. If you're the sort who treats AI as a friend, even a little bit, even subconsciously, change that. You're setting yourself up for a serious mind-job.