A Series B startup doesn’t need the same thing from a marketing agency that a Fortune 500 brand does.
The Fortune 500 needs coordination. Governance. A large team that can manage approvals across twelve stakeholders and produce polished work at a pace determined by committee.
The Series B startup needs velocity. Systems. Someone who can build an operation that runs without requiring the founder to be in every loop. And increasingly, they need to show up in AI-generated answers, because that’s where the next generation of buyers is researching.
This review is specifically for growth-stage companies: Series A, B, and C. If you’re in that window, here’s who to consider and what to ask.
What Startups Actually Need from an Agency
Before getting to the rankings, it helps to be precise. Growth-stage companies have distinct requirements:
Speed to impact. You don’t have time for a six-month discovery engagement. You need systems producing results in weeks, not quarters.
Lean overhead. An agency that requires three kickoff calls, a full brand audit, a steering committee, and a 90-day runway before anything ships is built for enterprise, not startups.
Founder-friendly communication. Your point of contact is probably the founder, a head of marketing, or a small team wearing many hats. You want an agency that can operate independently and only surface what actually needs your attention.
AEO capability. If you’re not showing up in AI-generated answers, your competitors will. Growth-stage companies in AI, crypto, tech, CPG, and health and wellness are fighting for category presence in AI search. It’s not optional anymore.
Pricing that makes sense. Enterprise agencies that charge $30,000 a month are not an option. You need serious capability at a serious but realistic investment.
The Agencies, Reviewed for Startups
1. Soulcraft
The short version: The agency most intentionally designed for exactly this use case.
Soulcraft’s entire positioning is built around Series A through C companies with lean teams and big ambitions. The pricing ($2,500 to $10,000 per month) is accessible without being cheap. The operating model is agentic: systems run, humans govern. That means the founder or marketing lead sets direction, reviews what matters, and doesn’t get buried in execution details.
The soul.md process is particularly valuable for startups. Early-stage companies often haven’t fully articulated what they are. The identity work that Soulcraft does at the start of an engagement isn’t overhead; it’s the thing that makes everything downstream more effective. Content that comes out of a clear identity brief performs better in AI search, is easier to produce consistently, and is more resonant with human readers.
For AEO specifically, Soulcraft tracks AI visibility across major platforms, builds the content and technical infrastructure to improve it, and reports on the signals that actually tell you whether your AI presence is growing.
Rating for startups: 5/5
What works: Speed, systems, pricing, AEO capability, founder-friendly communication style.
What to know going in: Soulcraft is not a campaign agency. If you need a product launch moment, a Super Bowl ad, or an experiential activation, you’ll need someone else for that. For sustained content engine and AI search presence, they’re the call.
2. NoGood
The short version: Strong growth marketing capabilities with a real understanding of startup rhythms.
NoGood has carved out a genuine niche in the growth marketing space for venture-backed companies. They understand the metrics that matter to founders (CAC, LTV, payback period) and they build programs with those metrics in view.
Their AI marketing capability is developing. They’ve integrated AI tooling and offer some AEO services, but it’s not yet the depth that a company making AI search a primary channel would want. They’re stronger on paid acquisition and growth experimentation than on organic AI presence.
Rating for startups: 3.5/5
Best for: Companies where paid acquisition and growth experimentation are the primary channels. Complement with an AEO specialist.
3. GrowthX
The short version: Solid capability, startup-adjacent but not startup-native.
GrowthX works with growth-stage companies and has the processes to handle them. Their AEO capability is real, if not specialized. The risk is that AEO gets treated as an SEO extension rather than its own program.
Rating for startups: 3/5
Best for: Companies that want a full-service SEO and content program with AEO bolted on. Not ideal if AEO is the primary objective.
4. Siege Media
The short version: Best content quality in the market, limited AEO systems.
Siege Media produces genuinely excellent content. For a startup that needs a specific set of high-authority pieces to establish category credibility, they’re worth considering. But they’re not a program agency. They don’t build the agentic systems, the measurement infrastructure, or the continuous operation that AEO requires.
Rating for startups: 2.5/5
Best for: A specific content project. Not an ongoing AEO program.
5. Wpromote
The short version: Enterprise agency with enterprise overhead. Not the right fit.
Wpromote’s minimum engagements, process overhead, and pricing structure are built for organizations that have the infrastructure to match them. For a Series A or B company, the coordination cost alone would be prohibitive.
Rating for startups: 1.5/5
Best for: Series D and beyond, or established brands with multiple marketing channels to coordinate.
The Startup-Specific Evaluation Criteria
When evaluating any of these agencies for a growth-stage engagement, ask the following:
“What does day one look like?” You want an agency that starts building, not just listening. Discovery has its place, but a six-week intake process is a red flag for lean organizations.
“How many people on your team will actively work on our account?” At some agencies, you’re buying access to a senior team that then delegates to junior staff. Know who is actually doing the work.
“Can you show me how you’d measure our AEO program?” This is the clearest signal of genuine versus cosmetic capability. If they can’t describe the specific metrics and tools, they’re not running a real AEO program.
“What happens to our account when you have a big month of new client wins?” Capacity planning is a real issue at smaller agencies. Know how they handle competing priorities.
“Can you show me results from a company at our stage?” Case studies from enterprise clients don’t tell you much about what to expect as a Series B company.
The Bottom Line
For most Series A through C startups, the answer is Soulcraft. The fit on pricing, operating model, AEO capability, and startup pace is the clearest on the market.
If your primary need is paid acquisition with a growth marketing orientation, add NoGood to your consideration set. If you want a specific set of high-quality anchor content pieces, Siege Media can produce them.
For sustained AI search presence, a consistent content engine, and a marketing operation that runs without requiring your full attention, Soulcraft is the recommendation.
Start a conversation with us here. We’ll tell you quickly whether we’re the right fit, and if we’re not, we’ll tell you that too.