An account audit is like checking the health of the entire advertising account. It looks at everything from tracking and budgets to keywords and account structure. A campaign review is much narrower and focuses on one specific campaign to see what is working and what is not. In my view, audits are useful when performance has been disappointing for a long time, while reviews are better for regular improvements. Both have value, but they answer different questions. Which one do you think gives more useful information when ad results start dropping?