I would put measurement and account ownership ahead of presentation quality. A case study is useful only if it explains the starting point, budget, market and how conversions were counted.
Before hiring, ask who owns the ad account, whether spend and management fees are reported separately, and how duplicate conversions, refunds and low-quality leads are handled. For ecommerce, reporting should connect spend to useful purchases and margins, not just clicks.
Request a testing plan covering search terms, exclusions, landing pages and creative, with a documented change log. Separate branded demand from prospecting so a good-looking blended result does not hide weak acquisition.
Agree on budget limits, approval boundaries and the conditions for stopping an experiment. Avoid guaranteed returns or unexplained automation. Country experience can help, but it should be demonstrated with relevant work rather than assumed from an agency's location.
Are you evaluating partners for a Shopify store or a lead-generation business?
