Run from rank guarantees
No one controls Google, so anyone guaranteeing a #1 ranking is either naive or dishonest. Good agencies talk about traffic, conversions and business outcomes, and are upfront that SEO takes months and isn't fully predictable.
Ask what they'll actually do
Make them explain their plan in plain language — technical fixes, content, authority — and how they'll report it. Vague "we'll optimise your site" answers mean either thin work or things they'd rather you didn't see. Ask who does the work and how senior they are.
Check for AI-search capability
In 2026, ask whether they work on AI-search visibility — getting you cited by ChatGPT and Google's AI answers — or just classic rankings. Many agencies haven't caught up, and that gap is where a lot of future traffic sits.
The hidden criteria most buyers skip
Two things separate a real partner from a vendor, and neither shows up in a pitch deck. First, who owns your accounts and data — the analytics property, Search Console, the site itself. A good agency builds these in your name and hands them over on day one. The ones who keep everything under their own login are holding your business hostage, and you only find out when you try to leave. Second, ask how they earn links. If the answer is vague, or involves buying placements and private networks, that's a tactic that can get your site penalised — and you're the one left with the cleanup.
How to read a case study
Case studies are theatre unless you press on them. A traffic chart means nothing without a baseline and a timeframe — a 300 percent jump from almost zero is easy. Ask which of those visitors turned into revenue, what the starting point was, and whether the client will take a reference call. The tell is specificity. Agencies doing real work can name the problem, the fix, and the metric that moved. Ones that can't will talk about "increased visibility" and change the subject.
Fit beats reputation
A famous agency built for enterprise budgets will quietly assign your small account to a junior and run a template. So match the shop to your size and stage. Pick a generalist when you need broad delivery across technical, content and links at scale. Pick a specialist when your problem is narrow and deep — a migration, a penalty recovery, or the AI-visibility gap. And be honest about your own capacity. The best plan in the world stalls if no one on your side can ship the recommended changes.