Marketing agency retainers represent an ongoing monthly commitment, which makes upfront vetting more important than for a one-off project, since a poor fit compounds in wasted spend month after month. Ask for case studies specific to your industry and business size, since an agency skilled at scaling a large e-commerce brand may not translate that expertise to a local service business with a smaller budget. Clarify exactly what reporting looks like — vague monthly summaries are a common way underperformance gets hidden, while specific metrics tied to actual business goals like leads or bookings indicate real accountability. Ask directly who will be working on the account day to day, since a strong pitch from senior staff sometimes hands off execution to junior team members with far less experience. Contract flexibility matters too — a reasonable agency will offer a shorter initial trial period rather than locking a new client into a full year upfront. Finally, ask how they handle underperformance against agreed targets, since the answer reveals whether the agency treats results as a shared responsibility or simply bills regardless of outcome.