Ask for references from businesses with a similar model, budget and target market, plus a sample report that separates media spend, agency fees and actual outcomes. For ecommerce, ask how they account for refunds, margin and returning customers.

Have them explain what they would change first in your store and why. A credible plan should connect research, landing pages, tracking and testing rather than promise rankings or followers.

Keep ownership of your accounts and agree on deliverables, approval limits and handover terms. Start with a defined diagnostic or pilot before committing to a large retainer.

What do you sell, where are your customers and which channel already produces purchases? Those details are more useful for choosing a partner than a generic 'best agency' list.