One HVAC owner paid an agency $14,775 for SEO, a website rebuild, and social media. Months of invoices later, his rankings had not moved, and his leads were still arriving the way they always had: through referrals. According to a case file BlitzMetrics published in 2025 and recounted in Formative Digital’s research on agency red flags, the monthly reports kept coming too, full of impressions climbing and “keywords ranked” growing. The phone kept not ringing.
I bring that case up first because it fails in a boring way. No dramatic penalty, no hacked site, no villain twirling a mustache. Just a business owner who did the reasonable thing, paying a professional, and a provider that billed for motion while producing none.
The five warning signs below have that same quiet quality. None of them is about results being slow. Slow is normal; SEO compounds, and it does it on its own schedule. The signs that matter are about structure: promises nobody can keep, work nobody will describe, numbers that measure nothing, and contracts that make leaving expensive.
The signs show up in month one. The regret shows up in month nine.
Here is the asymmetry that makes this topic worth an hour of your time. A bad agency looks identical to a good one during the pitch. Both show case studies, both talk about the algorithm, both want a retainer. The difference only becomes visible in the deliverables, and by the time you are reading those carefully, you have usually paid for a year of them.
So treat the list below less like a diagnosis and more like a checklist you run while the salesperson is still in the room. Every one of these is easier to spot before the contract than after it.
Sign 1: They guarantee a position
This is the oldest con in the business, and it is still the most common. Google states it flatly in its own hiring guidance: “No one can guarantee a #1 ranking on Google.” The company cannot tweak dials inside a system it does not operate, and its competitors are spending against you in the meantime.
Google Search’s John Mueller put the same point a different way when discussing who to hire: any SEO who makes promises about rankings or traffic from Search is waving a flag. If you want the primary source, Google’s “Do you need an SEO?” guidance is worth reading in full, because it also names the specific scams to walk away from: claims of a “special relationship” with Google, a “priority submit,” or guaranteed placement in AI Overviews and chatbot answers.
What can a good SEO promise? A process, a timeline, and a measurement plan. Not a slot.
Sign 2: Nobody can tell you what the work actually is
Google’s advice on secrecy is about as direct as corporate documentation gets: be careful if a company will not clearly explain what it intends to do. If your account manager answers “we optimize for the algorithm” when you ask what happens next week, you have learned something.
There is a second version of this that is sneakier, because the pitch is loud and the delivery is quiet. A senior strategist runs the sales call, then the account is handed to a junior who never appeared in the proposal. Agencies call it capacity management. Clients experience it as a phone that stops ringing. Ask one question before signing: which named person will do the work on my account, and can I meet them now? An honest agency puts that person on the call and lets them sign the report.
Sign 3: The report measures motion, not money
Mueller has been blunt about this one for years: the classic low-quality SEO play is to charge a retainer and then report on every query the site ranked for, including nonsense strings nobody would ever type. Impressions and “keywords ranked” are easy to inflate and impossible to bank.
A report worth reading connects organic sessions to conversions, and conversions to leads, pipeline, or revenue. That means the agency should be working inside GA4 and, ideally, your CRM, not a third-party tool that shows a suspiciously smooth line going up and to the right. If the dashboard cannot tell you how many qualified leads organic search produced last month, the report is decoration.
Sign 4: The link building is a black box, or a scheme
Links still move rankings, which is exactly why this is where the quiet damage happens. Google’s spam policies define link spam as creating links “primarily for the purpose of manipulating search rankings,” and they list the usual suspects: bought links, private blog networks, automated link services, optimized anchors in guest posts and press releases. The enforcement is real; unnatural inbound links can trigger a manual action that files away months of your work.
None of this means link acquisition is off-limits. It means the provenance matters. Paid placements are allowed when they are qualified with rel="sponsored", and if you want to get the vocabulary straight before you audit what was already done to your profile, a plain-English explainer on backlinks for seo is a reasonable place to start. The test for your agency is simple: ask for the list of sites it built links on last quarter. A real program has one. A scheme never will.
Sign 5: Leaving would cost you your website
This is the one that turns a disappointing vendor into a hostage situation. If your domain, hosting, content, GA4, Search Console, and Google Business Profile sit in the agency’s name, you do not have a service provider. You have leverage working against you.
Formative Digital documents a case in which an agency took down a client’s website and Google Business Profile and demanded another $8,000 to release them, after doing no meaningful work. It sounds extreme until you meet the softer version: a 12-month contract with no exit clause, which at $800 a month is $9,600 spent before you are allowed an opinion. The fix takes ten minutes on day one. Put your name on every account and confirm it in writing.
Hold on. Aren’t long contracts normal?
Yes, and this is where I part ways with the loudest take on the subject. A three-to-six-month initial commitment is reasonable. SEO genuinely does take months before the compounding shows up, and an agency that will bail after four weeks is not obviously better than one that asks for a quarter. The number of months is not the red flag.
The red flag is duration without accountability. A fair contract defines leading indicators at 90 days, expected outcomes by six months, and what happens if neither materializes. A confident agency earns the renewal. One that insists on a year with no performance milestones is protecting its revenue, not your rankings.
The green flags that matter more than the pitch
Strip away the branding, and the whole decision comes down to transparency and alignment. Here is how the two columns compare in practice:
Table synthesized from Google Search Central’s hiring guidance and the 2026 red-flag checklists published by Formative Digital and Derivatex; checked September 2026.
There is one more check that is easy to skip, and it involves the reviews you used to shortlist the agency in the first place. The U.S. Federal Trade Commission’s rule on consumer reviews and testimonials has been in effect since October 21, 2024, and it bans buying or selling fake reviews and using insider testimonials that hide the relationship. That matters to you because the rule makes both the agency and the business on whose behalf the fake reviews were created potentially liable. The FTC’s own guidance on the rule walks through who can be held responsible. So if the agency’s testimonials look suspiciously uniform and all arrived in the same week, that is not just a marketing quirk.
