Machines will be able to do that too. Hell, non-AI algorithms are already doing that - e.g. social media algorithms picks what should be promoted to individuals; of course they are working for the social media company rather than those individuals but my point still stands.
"What to do" has lots of different layers. AI might be able to decide which ads to promote to individuals, but can it decide the weightings of the factors it takes into account to make that decision? Can it decide to promote ads to individuals in the first place?