Agency, in-house or growth department? The options YC founders choose, compared

Most founders leave Demo Day or close a seed round with the same to-do item near the top of the list: sort out growth. The first customers came from the founders themselves. Now the board, the investors and the runway all want a repeatable engine, and the founder's calendar is already full.

The market offers seven ways to answer that. This article compares them by type, never by name, and is fair about where each one is the right call. It then shows where a growth department fits, with results from two engagements.

What are the growth options after Demo Day or a seed round?

There are seven common options: a performance agency, an outbound or SDR agency, a content or SEO studio, a GTM consultancy, a part-time CMO, an in-house hire, and a growth department. They differ less in skill than in what they own.

• Performance agency. Runs paid search, paid social and ad creative. Paid on retainer or a share of spend.
• Outbound or SDR agency. Builds lists, writes sequences and books meetings on your behalf.
• Content or SEO studio. Produces articles, landing pages and search work on a content calendar.
• GTM consultancy. Diagnoses your go-to-market, writes the strategy and the playbook, then leaves.
• Part-time CMO. A senior marketer for a few days a month who sets direction and manages vendors.
• In-house hire. Usually a first marketer, or a VP of Marketing hired to build the function.
• Growth department. One senior team that runs strategy and every channel together, under one lead.

Paul Graham wrote that at least one founder, usually the CEO, will have to spend a lot of time on sales and marketing. That is still true after Demo Day. The question is what the founder's time is spent on: selling, or managing the people who were meant to take selling off their plate.

How do growth agencies compare with in-house hires and a growth department?

The clearest way to compare them is by who owns the pipeline number, how fast pipeline starts, whether strategy is included, how many vendors you manage and how much founder time each one takes. On those criteria, the options sort into three groups: channel specialists, advisers and owners.

Two more criteria separate the options sharply: what happens when a channel fails, and how the model scales. With a single-channel vendor, a failing channel means the vendor defends it or you fire them. Nobody moves the budget elsewhere, because nobody else is in the room.

Scaling works the same way. Agencies scale by adding spend or seats in the channel they run. In-house teams scale by hiring, one role at a time. A department scales by moving budget and volume to whatever converted, across every channel it runs.

Strategy is the quiet difference. Three of the seven options include it, and only one of those also executes it. When strategy and execution sit with different people, the gap between them lands on the founder, who ends up translating the consultant's deck into briefs for the agencies.

Vendor count matters more than it looks on paper. Every vendor brings its own reporting, its own definition of a lead and its own monthly call. Three vendors means three versions of the truth, and the founder reconciles them at night.

When is a growth agency the right call?

An agency is the right call when the channel is already proven and you need more volume from it, not a decision about what to do. Agencies are specialists, and specialists are excellent at doing one known thing more.

Performance agency

Hire one when a paid channel already converts and the job is to scale spend efficiently. If you know your cost per qualified meeting from paid search and it holds as budget rises, a good performance agency will run it better than a founder can. Do not hire one to find out whether paid works, because the agency is paid either way.

Outbound or SDR agency

Hire one when your message is proven in founder-led sales and you need reach. The agency brings lists, sending infrastructure and volume. It does not bring your proof, your point of view or your relationships, so you still write the message and supply the case studies.

The usual failure is a sequence that sends a lot and books little, followed by a debate about lists. Meetings booked are not qualified pipeline, and an agency counting meetings is measuring the step before the one you care about.

Content or SEO studio

Hire one when your category has search demand and you already know what your buyers ask. A studio produces well. It rarely decides what the company stands for, and it rarely connects content to the accounts sales is working.

GTM consultancy

Hire one when you need an outside diagnosis and you already have people to execute it. The strategy is often good. The gap is that it arrives as a document, and the founder is left to turn it into channels, hires and vendors.

When does a part-time CMO or an in-house hire make sense?

A part-time CMO makes sense when you need senior judgement and already have people or vendors doing the work. An in-house hire makes sense when a working system exists and needs someone to run and extend it.

A part-time CMO gives you strategy at a sensible cost. What they rarely give you is hands. They direct the agencies, so you keep every vendor relationship and add one more person to coordinate. Ownership of the number is shared, which in practice means nobody holds it.

The in-house route splits into two mistakes. The first is a junior first marketer, hired to do everything and left isolated, with no senior peer to set strategy and no budget authority. The second is a VP of Marketing hired too early, who arrives to a blank page and spends the first two quarters hiring and buying the vendors the agency route would have given you on day one.

Hiring also takes time to pay back. The Bridge Group's 2025 research on SDR teams puts average SDR ramp at 3.0 months and average SDR tenure at 1.9 years. A team built one hire at a time spends a meaningful part of each person's tenure getting them productive, and the founder does most of the training.

None of this makes in-house the wrong answer forever. It makes it the wrong first answer. Once a system is producing qualified pipeline with clear numbers, a hire has something proven to run and a target that means something on day one.

What is the difference between buying channels and running a department?

Buying channels means hiring one vendor per channel and integrating them yourself. Running a department means one team owns the outcome across every channel and moves effort to what converts.

B2B buyers make the channel-by-channel model harder still. Peter Weinberg and Jon Lombardo of LinkedIn's B2B Institute set out the 95:5 rule: only 5% of B2B buyers are in market at any time. A single outbound vendor hunts that 5%. Brand, executive content, events and partners are what keep you remembered by the other 95% until they move in market.

Our own engagements show the same pattern. At the cybersecurity services firm we worked with, 8 in 10 opportunities were touched by three or more channels, and it took an average of 5 touches before the first call. No single-channel vendor owns a journey like that.

Where does a growth department fit for a YC startup?

A growth department fits the stage right after product-market fit, when the founder has proven the product sells but nothing outside the founder produces pipeline yet. A growth department is one senior team that owns qualified pipeline end to end, from strategy to execution, under a single accountable lead.

That lead owns the qualified pipeline number and can move budget between channels within the quarter. The account list is agreed with sales. Positive replies and signals reach sales the same day, and pipeline is reviewed with leadership every month, account by account. You can read the full model on how we work.

Codax runs this as a dedicated growth department for B2B companies, using Signal-Based ABM. That means reading every signal inside the business, from revenue deal by deal to why customers bought, and in the market, from who is researching the category to competitor moves, then deciding strategy and execution together from it.

What it looks like in practice

The agentic AI healthcare firm had strong search and product-led growth but no outbound, LinkedIn or email. In seven months it closed $1.02M ARR from LinkedIn and email, channels that had produced none, and built $7M in qualified pipeline. It added 0 hires to do it.

The cybersecurity services firm had no marketing function, and every deal came from referrals and the founder's network. Three months of repair came before the first outbound sequence. In twelve months, yearly qualified pipeline grew from $548K to $2.2M.

The healthcare firm's tests show why owning every channel matters. Leading with the CMIO produced 2.1x the meetings. Retargeting produced meetings 4x cheaper than cold titles. Adding a user track doubled replies. Each of those findings changed where budget went the next month, which only works when one team controls the budget.

The cybersecurity firm's biggest unused asset was its Google Cloud security partnership. A channel vendor would never have found it, because it sits outside any single channel. Within the year it produced $132K in yearly partner-sourced pipeline, alongside $247K in yearly pipeline from events.

Neither result came from one channel. Both came from fixing the foundation first, testing channels against an agreed account list, and moving budget to what converted. That is the work no single vendor is set up to do.

How should a YC founder choose between these options?

Choose by what is already proven and by who will own the number. Work through the questions below in order, and stop at the first one that gives a clear answer.

Most founders we meet land on the last question. They have product-market fit, a handful of customers won personally, and two or three vendors who each report a different number. If that is you, our piece on why YC founders stall on growth explains how the stall forms, and what a growth department is sets out the model in full.

What does a growth department ask of the founder?

A growth department asks for about one hour a week from the CEO, one to two hours a week of founder voice captured from recorded interviews, and about one hour a week from subject-matter leads. Everything else is run by the team.

The founder's voice stays central, because it converts. At the healthcare firm, the CEO as the sender produced 3x the replies. At the cybersecurity firm, founder-signed invitations produced 3x the acceptances. The difference is that the founder is the voice, not the operator.

Every engagement starts with an assessment: a written report of everything found, a prioritised repair list, a first read on the account list and a recommended plan across the five phases. You know what is broken and what will be built before anything is sent.