Listicles call themselves "best."
Buyers know better.

Run four parallel checks. First, evaluate the operator stack, who actually does the work day-to-day, and how senior are they? Junior-led engagements at senior pricing are the most common bad outcome. Second, ask for two reference calls with current clients in similar revenue bands and competitive categories: not the agency's all-time best case studies. Third, request the audit deliverable that comes before the engagement; the quality of the audit is the single best predictor of the engagement quality. Fourth, look at the founder's published work: books, original-data studies, conference talks, contributor bylines on Forbes or Search Engine Land. Operators who publish methodology have a public reputation that disciplines their work; operators who don't publish have nothing forcing accountability beyond the contract.

It depends on what you are buying. Larger agencies may offer broader bench coverage, mature process, and more execution capacity. A boutique may offer more direct senior involvement and faster decisions, with greater concentration risk. Ask who will own the account, who will do the work, how absences are covered, and where specialist support comes from. Choose the operating model that fits the scope rather than an arbitrary headcount or revenue band.

Hire for the constraint you actually have. Relevant vertical experience can matter in regulated or technically specialised markets, but it is not a substitute for sound diagnosis. A generalist may be the better fit when the problem crosses technical SEO, content, measurement, and conversion. Ask each operator to explain how the proposed work changes for your market, what evidence supports the priority, and which claims they cannot responsibly make yet.

A case study is useful when it identifies the starting point, scope, measurement period, source data, material constraints, and what the agency actually controlled. Check whether the metric is traffic, qualified demand, pipeline, or revenue, and whether the comparison is genuinely relevant to your business. Client confidentiality can limit references, so the absence of a call is not proof of failure. The better test is whether the evidence is specific, internally consistent, and presented without hiding important caveats.

Look for a clear scope, named responsibilities, approval rights, data access, reporting cadence, ownership of work product, confidentiality, payment terms, change control, and an exit process. The right commercial term depends on the work being commissioned, so no single contract length protects every buyer. Have your legal adviser review material commitments and make sure any result, timeline, or deliverable claim in the proposal is reflected accurately in the agreement.

SEO scope varies with site size, market competition, implementation responsibility, content needs, reporting, and internal capacity. That makes a universal price misleading, but it does not excuse vague proposals. A useful agency explains which factors change the fee, what is included, what is excluded, and how a scope change will be handled. Published ranges can help, but the final quote should still be tied to the evidence and responsibilities in the engagement.

Commit only after the agency explains the work, dependencies, leading indicators, commercial measures, and review points. SEO timing varies by site history, competition, implementation speed, crawl behavior, and the type of change being made. Your planning horizon and contract term are separate decisions. Agree how progress will be reviewed and what happens if access, implementation, scope, or evidence changes.

Raise the problem in writing and separate missing deliverables, weak communication, implementation blockers, and disappointing results. Ask for the agency's evidence, a named owner, and a specific corrective plan. If the response does not restore confidence, follow the exit terms in the agreement and secure the data, work product, access, and documentation you are entitled to receive. Clear escalation protects both sides better than silent dissatisfaction.