Do You Need a Growth Marketing Agency or an SEO Agency?
A growth marketing agency runs tests across your whole funnel to lift conversion, while an SEO agency builds how buyers find you in search and AI answers. Which one you need depends on where your pipeline leaks, not on which label sounds more modern.
Where do your buyers stop? Do they never find you, find you and never click, or click and never convert? Which of those could one retainer fix?
We're an AI SEO agency, so we'll say plainly where a growth agency is the better hire. Let's look at the two side by side, and then at a quick check you can run yourself.
Key takeaways
- Growth agencies optimize the funnel, SEO agencies build discovery
- The bottleneck decides the hire, not the label
- Search Console and GA4 show where buyers drop off
- Some teams need both, so sequence them
What Does a Growth Marketing Agency Do?
A growth marketing agency runs experiments across the funnel to increase qualified leads and revenue. The work spans paid acquisition, landing pages and conversion testing, lifecycle email, and sometimes product-led tactics.
The unit of work is the experiment: a hypothesis, a change, a measured result. That makes growth agencies strong when you already have traffic and need more of it to convert.
It also makes them dependent on traffic that exists, because a test needs enough visitors to say anything. Testing a button on a page nobody visits produces a confident chart and no information.
The label is loose. Some agencies that call themselves growth shops mostly run paid media, and others own the whole path from click to sales handoff. Ask what the retainer covers before you assume.
Conversion testing alone is a specialty of its own, covered in our guide to what a CRO agency does.
B2B changes the work. Sales cycles run longer and involve several buyers, so a B2B growth agency has to follow a lead through to pipeline instead of stopping at the form fill. A growth agency that reports clicks and cost per lead but can't tell you which leads became opportunities is measuring the cheap half of the problem.
What Does an SEO Agency Do?
An SEO agency works to make your site findable in Google Search and to get your brand cited in AI answers from ChatGPT, Perplexity and Google's AI Overviews. In 2026 that covers technical fixes, content architecture, internal links and the third-party sources AI engines retrieve and cite, alongside the older ranking work.
The unit of work is the page, or the cluster of pages around a topic. A page built well and kept current can keep earning visibility after the invoice is paid, which is why SEO suits teams that want a channel that compounds. Our SEO marketing agency guide covers the scope in full.
AI search has changed what an SEO agency is for. Some buyers now read a shortlist in ChatGPT before opening a single site, so an SEO agency's job includes working to get your brand named in those answers, not only ranked beneath them. An agency that still describes SEO only as rankings is describing a narrower job.
SEO also has limits. An SEO agency can send a steady stream of qualified visitors to a page that converts like a locked door, and it can't fix that page once buyers arrive. A good SEO agency measures on pipeline instead of traffic for exactly that reason.
How Do the Two Differ?
The two differ in what they work on, how they're measured and what they can't fix. This table sets them side by side.
| Growth marketing agency | SEO agency | |
|---|---|---|
| Main job | Lift conversion across the funnel | Make you findable in search and AI answers |
| Unit of work | The experiment | The page or topic cluster |
| Typical channels | Paid, landing pages, email, lifecycle | Site, content, links, third-party sources |
| Measured on | Qualified leads, cost per lead, revenue | Qualified organic visits, mentions in AI answers, pipeline |
| Time to signal | When a test has enough traffic | In our SEO engagements, results are typically visible within 30 days and pipeline impact typically within 60 to 90 days |
| Can't fix | A funnel nobody reaches | A page that doesn't convert |
Read the last row twice. Each agency's blind spot is the other's specialty. The same split separates SEO from inbound programs, which we compare in inbound agency vs SEO agency.
When Is Each the Better Hire?
A growth agency is the better hire when buyers already reach you in volume and too few of them convert. That looks like steady traffic, a landing page that hasn't been tested in a year, and a lead form with a drop-off nobody has measured. A shorter sales cycle and a product people can try before they buy also favor growth work, because tests resolve faster.
An SEO agency is the better hire when the right buyers can't find you. That looks like a strong product and a decent site that doesn't appear for the queries your buyers use, or doesn't get named when they ask an AI assistant for a shortlist. It also suits teams that want a channel that compounds, since well-maintained owned pages can keep earning after the work is done.
Neither agency fixes a product or sales-process problem on its own, though some growth agencies cover the handoff. If traffic converts and deals still stall, start with your own pipeline review.
Which Problem Do You Have?
Your pipeline leaks at one of three points: buyers don't find you, they find you and don't click, or they click and don't convert. Hire for the leak, not the label. This quick check shows where yours likely sits.
- In Search Console's Performance report, filter to the queries a buyer uses when ready to hire (service, category and comparison terms) and note impressions over a recent period such as the last month.
- Check clicks, click-through rate and average position for those same queries. Few clicks at positions near the top suggest a snippet or intent problem, while few clicks at lower positions suggest a ranking problem.
- In GA4, open the landing page report for organic traffic and note the key events each page produces.
- Compare those pages with the same pages' paid or direct visitors, if you have them.
- Read the pattern against the three leaks below.
Thin impressions on buying-intent queries suggest buyers don't find you, which points to an SEO problem. Search Console shows only the queries where you already appeared, so pair it with a keyword tool's demand estimate before you decide. Few clicks on queries where you do appear point to a snippet, title or intent problem, which a good SEO agency handles too.
Strong impressions and clicks with weak key events, the GA4 actions you mark as important to the business, suggest buyers arrive and leave, which is a growth and conversion problem. Strong numbers everywhere with stalled deals point at the sales process. If the gap is demand rather than leads, the split in demand generation vs lead generation decides the next move.
This check covers Google Search only. ChatGPT and Perplexity don't report into Search Console or GA4, so test five or so buyer questions there by hand.
Here's a hypothetical. A head of marketing sees healthy traffic to the pricing page, a form that converts poorly, and almost no impressions for the category terms buyers search before they reach it. The pricing page is a growth problem, and the missing impressions are an SEO problem, so one reasonable sequence is to start discovery work now and run the quick form fix alongside it this quarter.
Our rule of thumb, and it's a default rather than a law, is to start discovery first when impressions on buying queries are thin. A perfectly tested page nobody reaches is a well-lit empty room.
Can One Agency Do Both?
Some agencies do both, and the trade-off is coverage against depth. A full-funnel agency coordinates more of the path but spreads its specialists thinner. A specialist goes deeper in one area and leaves the handoffs to you.
The deciding question is who coordinates on your side. If you have a head of marketing who can direct specialists, two focused partners are easy to run. If the founder still owns marketing, one accountable partner is easier, even at some cost in depth.
What Should You Ask Before Hiring?
Ask five questions before you sign with either type of agency, because the answers can help separate real operators from good slide decks.
- Which metric do you own, and who signs off on it?
- What do I see every week, and in which dashboard?
- What's in the retainer, and what isn't?
- What happens at month three if signals are flat?
- What will you tell me not to buy?
The last question is the useful one. An agency that can name something you shouldn't buy is showing you it has thought about your problem rather than its own pipeline.
FAQs
What does a growth marketing agency do?
A growth marketing agency runs experiments across the funnel to raise qualified leads and revenue. Its work usually spans paid acquisition, conversion testing, landing pages and lifecycle email. Scope varies by agency, so check what the retainer covers.
Is SEO part of growth marketing?
SEO can be one channel inside a growth program, but the two aren't the same job. Growth work tests and improves the funnel, while SEO builds discovery in search and AI answers. Some growth agencies include SEO, and many don't go deep on it.
Which is better for B2B SaaS?
The better hire depends on the leak. If buyers don't find you on the queries that matter, SEO comes first. If they find you and don't convert, a growth agency or conversion specialist comes first.
How long does each take to show results?
A growth test shows a result as soon as it has enough traffic to read. SEO builds as pages get indexed and earn visibility. In our engagements, first website changes land within 15 days, and results are typically visible within 30 days, with pipeline impact typically within 60 to 90 days.
How much does each cost?
Prices vary with scope, team size and channel spend, and we don't publish ours. Ask each agency what the retainer covers, what it excludes and whether media spend is separate.
Find the Leak Before You Hire
The right agency is the one that fixes the leak you have, so run the Search Console and GA4 check before any sales call. Discovery work, in search and in AI answers, is what Tenpoint Labs does as an AI SEO agency, measured on pipeline, with Tenpoint Analytics giving clients the same view we use. If the check points to conversion, hire the specialist and come back for discovery later.
