SEO agencies get clients from referrals, their own content and rankings, partner agencies, directories such as Clutch, events, free audits and outbound. The first six mostly depend on someone else's timing. Outbound is the one where the agency decides who hears from it and how often.
Outbound here means a list of companies that look like your best clients, contacted directly on LinkedIn and by cold email. Because you choose how many people you reach, it is also the easiest channel to size before you start.
For one SEO agency in Switzerland, my team ran multi-channel outbound together with content marketing on LinkedIn. Over three months that produced 215 sales calls, and the agency signed 24 contracts. The LinkedIn numbers from that campaign are laid out further down.
Where do SEO agency clients usually come from?
Every channel on the usual list is real. What separates them is who decides when the next lead shows up.
| Channel | What it depends on | Who sets the timing |
|---|---|---|
| Referrals | Happy clients meeting someone who needs you | Your clients' conversations |
| Your own content and rankings | Months of publishing before trust builds | Search engines and your publishing pace |
| Partner agencies (web design, content) | The partner's pipeline and goodwill | The partner |
| Directories such as Clutch and Manifest | Reviews and where your profile sits inside the directory | Buyers who happen to be searching there |
| Events and online communities | Your hours in the room or the group | The event calendar |
| Free audits | A prospect agreeing to receive one | The prospect |
| Outbound on LinkedIn and cold email | A targeted list, a clear message, enough volume | You |
Referrals pay off, and they start slowly. Cody Miles, founder of BrandCave, told AgencyAnalytics (August 2025) that growing by referral "took about 6-8 months before we began seeing any real return".
He adds that it then snowballed, as clients recommended the agency to their peers.
That is a fair trade if you can wait eight months. If payroll depends on the next client, you also need a channel that responds to effort this quarter.
Where your own content fits
Your content and your own rankings make a sales conversation easier once it starts. They rarely start it. The likes and the traffic pile up, and somebody still has to open the conversation that ends in a signed retainer.
So content works best as support for outbound, sitting behind it, rather than as a replacement. How long content takes to earn trust is answered in my founder content Q and A, and the honest answer there is longer than most founders would like.
Who should an SEO agency target first?
In a 2023 LinkedIn post that broke down an SEO company's campaign, the first step I listed included this line: "Check the past/current clients, find similar companies you can target."
An SEO agency is in a better position than most to do this, because its client list is already a data set. Look at which clients got the clearest results, which stayed the longest and which paid the most. Those clients point to an industry, a company size and a buyer title.
Say six of your strongest retainers are B2B software companies with a small in-house marketing team. Then the list is B2B software companies of that size, the person you contact is whoever owns inbound pipeline there, and the message talks about the searches their buyers make.
The pitch that fails here is "we do SEO for any business that wants more traffic". A message written for every company reaches none of them in particular.
One Swiss SEO agency, 215 calls in three months
Smirnov Consulting Group is a Prague-based B2B outbound lead generation agency that runs cold email and LinkedIn campaigns for founder-led B2B companies and books qualified sales calls. This campaign, for an SEO agency in Switzerland, is one of the case studies published on our site.
It combined multi-channel outbound with content marketing on LinkedIn. The groundwork: LinkedIn profiles optimized, email set up, two specific buyer groups targeted, and lead lists built with RocketReach and from niche websites found on Google.
The screenshots in the case study cover the LinkedIn side, from two sender accounts:
- Account 1: 49 connections, 441 profile views, 45 replies
- Account 2: 567 profile views, 222 replies
They also show the LinkedIn message funnel, with three steps and a conversion rate for each:
| Funnel step | From | To | Conversion |
|---|---|---|---|
| Step 1 | 547 | 134 | 24% |
| Step 2 | 392 | 81 | 21% |
| Step 3 | 46 | 7 | 15% |
Result for the whole campaign: 215 sales calls and 24 signed contracts in 3 months.
Three things in those numbers are worth your attention.
First, on the LinkedIn side, the two accounts landed far apart inside the same campaign. Account 2 collected 222 replies, close to five times the 45 on Account 1. Judge each sender account on its own numbers before you decide whether the channel works.
Second, the two profiles were viewed 1,008 times over the campaign. People looked up who was writing to them. Whatever sat on those profiles was part of the pitch.
Third, a little over 11 in every 100 sales calls became a signed contract. That ratio drives the contact math further down.
The Swiss agency was not a one-off for this niche. A different SEO company, in Singapore, got 78 sales calls in its first 30 days of working with us and 1,344 in the 12 months before I published the result in May 2023.
What it takes to turn that many calls into revenue is the subject of a separate piece on closing booked calls.
Is cold outreach just blind fishing?
The Traffic Think Tank guide to finding SEO clients says "Sending cold messages on LinkedIn is like blind fishing." The AgencyAnalytics roundup says getting SEO clients "isn't about sending cold emails or blindly advertising your SEO services."
Both put "cold" and "blind" side by side. They describe different things. Cold means the prospect has not heard from you before. Blind means you never chose who to contact.
The Swiss campaign went to lists built around two chosen buyer groups, and every step of its LinkedIn message funnel converted at 15% or better. You can judge for yourself whether that looks like a net thrown into the ocean.
To be fair to the Traffic Think Tank guide, it does recommend tailored outreach found through LinkedIn's advanced search. Targeted outbound is that same idea, run at a volume large enough to plan around.
How many people does an SEO agency need to contact?
Work backwards from the clients you want, and never forward from a sending quota. You need two ratios.
The first is booked calls per signed contract. In the Swiss campaign it was 215 calls for 24 contracts, so about 9 calls per new client. Treat that as a reference point. Your own sales process sets your real ratio.
The second is people contacted per booked call. That figure moves with three things: which niche you sell into, which country you target and which channel carries the message. In my own campaigns it has landed between 150 and 250, the same range I size markets with in how I pick a market.
Keep that range apart from the Swiss numbers. The 215 calls came from three months of multi-channel outbound plus content on LinkedIn. The 150 to 250 range is a planning ratio for cold outreach in general. Take the calls-to-contracts ratio from the Swiss case and the volume from the range.
A worked example of checking that a narrow niche holds enough buyers for that range is in my piece for consultants and fractional executives, and the same check works for an agency.
Put both together and you get the table below. These are planning figures, not results from a campaign.
| New retainer clients per quarter | Booked calls needed (about 9 per client) | People to contact per quarter | People to contact per month |
|---|---|---|---|
| 3 | 27 | 4,050 to 6,750 | 1,350 to 2,250 |
| 6 | 54 | 8,100 to 13,500 | 2,700 to 4,500 |
| 12 | 108 | 16,200 to 27,000 | 5,400 to 9,000 |
A more cautious version of the same math appeared in a LinkedIn post of mine from April 2024: at least 10,000 people contacted a month for 30 to 35 B2B sales calls, depending on the industry. That works out to roughly 290 to 330 people per call, above the 150 to 250 range the table is built on.
Until your own campaign gives you real ratios, the safer plan uses the higher numbers.
Set the target from what your team can deliver
Read the table from the left. Pick the number of new retainers your team can actually onboard in a quarter, then run the volume for that row.
The other direction goes wrong in a predictable way. Since late 2024, one condition keeps coming back when I describe who we work with: the client will not ask us to pause campaigns because they are too busy to take on more business.
For an SEO agency, every new retainer brings onboarding work. If the calendar fills faster than the team can deliver, the temptation is to switch outreach off, and then the pipeline for next quarter stops with it.
Will a prospect check an SEO agency's own site?
Expect it. An SEO agency writes to people who can judge online credibility themselves. The prospect may open your website, read a case study, and run your domain through the same tools you would sell them.
In B2B, people decide after they have looked you up, and the email only starts that check. The 1,008 profile views on the two Swiss campaign accounts show the same habit on LinkedIn.
So the proof goes into the first message. In the 2023 post about the SEO company's campaign, one step was to put proof inside the message itself: earlier clients, their results, the case studies.
For an SEO agency, that means three things:
- One checkable result in the message. A shape like "[type of client], [metric] from [before] to [after] in [months]", using a client you have permission to describe.
- A case study page that holds the same number. If the email says one thing and the site says another, the prospect notices.
- A sender profile that matches. The person whose name is on the message should state what the agency does and for whom, in plain words.
Three mistakes that stall SEO agency outbound
Pitching the service instead of the meeting. All the opening message has to do is get a reply. A paragraph on your SEO process and packages is a pitch to a stranger, and a stranger who gets pitched in message one usually stops reading.
An unrequested list of errors on the prospect's site is a pitch too, however generous it feels.
Treating the call as free. The call costs you nothing. For the prospect it is time they may not get back, which means the message has to make the case: why this call, why for them, why now.
Contacting too few people. In that April 2024 post I described B2B companies that run outbound by sending around 200 messages a month and then wonder why new clients are hard to find. Against the table above, 200 messages a month is a small fraction of even the smallest row.
Short answers for SEO agency owners
Should an SEO agency start with LinkedIn or cold email?
Plan for both. The Swiss campaign combined multi-channel outbound with content marketing on LinkedIn and produced 215 calls in three months. One LinkedIn account can only reach so many people a month, so when the table asks for more than your accounts can contact, cold email carries the extra volume.
How many people does an SEO agency need to contact for one new client?
As a planning figure, roughly 1,350 to 2,250 people per signed client. That uses 150 to 250 people contacted per booked call and the Swiss campaign's ratio of about 9 calls per contract. Measure your own ratios after the first month and replace these.
Should the first message offer a free SEO audit?
I would not lead with one. A full audit is real work built for one company, and handing it over for free turns the sales process into an audition. Put a checkable result from a past client in the message instead.
If someone insists on a tailored review before they commit, make it a small paid piece of work. The longer version is in what five days of unpaid work taught me.
How long does outbound take to produce SEO clients?
The Swiss agency's 215 calls and 24 contracts all came within three months, and the Singapore company had 78 calls in its first 30 days. Before the first message goes out, the list, the message and the sender's profile have to be ready. After the calls start, contracts follow at the speed of your own sales cycle.