When researching <a href=https://www.linkedin.com/pulse/google-ads-marketing-agency-5-best-2026-how-pick-right-one-j2tqf/>google ads agency</a>, start with campaign ownership, tracking quality, reporting clarity, and access to the advertising account. Case studies are more useful when they include starting conditions, time periods, budgets, limitations, and the exact metric being improved. No agency can guarantee outcomes, but it should be able to explain its assumptions, methods, and decision-making process.