The AdWords conversion rate optimizer is useful, but it’s not magic. It works best only when you’ve already got solid conversion data for it to learn from. Without that, it’s just guessing. New campaigns or low-traffic ones won’t give it enough to work with, which means the algorithm can’t really optimize much. It's also reactive, not proactive, so sudden shifts in customer behavior or changes to your site or offers can throw it off. And since it focuses only on measurable conversions, it won’t help with awareness or long-term brand engagement.