How to Choose a Growth Marketing Agency: 11 Founder to Founder Tips

I truly believe that most growth marketing agencies are determined to do the very best job that they can for their clients. When this falls down, it’s most often due to a mismatch of experience or expectations. 

I’m the co-founder of a growth marketing agency co-founder, and I also regularly vet micro agencies for Growth Division’s expert network. So I’ve seen both sides of how this choice works, and I’ve seen how important it is to really feel each other out and communicate well in those early meetings.  

With this in mind, these are my 11 tips for choosing a growth marketing agency for your startup or fast-growing business. 

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1. Check third-party reviews, not just case studies

💡 In short: Case studies can be skewed. Look for thorough reviews on independent sites (such as Clutch) instead. 

We love collecting reviews for Growth Division via Clutch because they are so incredibly thorough, and actually useful and reassuring to potential clients (most of whom are marketing-savvy, so naturally sceptical!). They can read the full story of the engagement in our clients’ words, and really dig into how the process looked from their side. You can also use Clutch as a search tool for agencies or other service providers.  

It’s all too easy to make case studies sound more impressive than they actually are. That 200% increase in site traffic? It could mean taking traffic from 5 sessions to 15. Even testimonials can be strategically clipped to show the agency in its best light (that ‘But…’ sentence conveniently dropped). 

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2. Speak to past clients

💡In short: It’s always valuable to speak to a past or current client if the option is there. Don’t be afraid to dig deep if you do. 

There’s also no harm in asking to be put in touch with one of the agency’s past or current clients directly. This is most useful when there’s a clear overlap with your type of business or the problem you’re trying to solve. 

If you do get this contact, make the most of it. Having a friendly team, delivering work on time… these things should more or less be a given. Go deeper: ask about the process, the results, and how working together affected their business in the long term. 

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3. Decide whether you want thinkers or doers (or both) 

💡In short: I recommend finding a growth marketing agency that can do both strategy and execution, and do both well. One or the other can still work under the right circumstances. 

Many marketing agencies specialise in either strategy or execution, and some do both well. For growth marketing, I’d really recommend working with an agency that does both, because the strategy should be continually influenced by the results of the day-to-day work. 

Ultimately, though, it’s up to you. Strategy alone may work fine, as long as you’re realistic about the capabilities of your in-house team. Execution alone can also work if you’re ready to be really hands-on, the tracking is tight, and you have really good communication with the agency. 

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4. Ask who will actually be working on your account 

💡In short: You’re coming to this agency for their experience, so make sure your work isn’t being farmed out to their most junior team members.  

On discovery calls with potential clients, one of the most consistent gripes I hear about their past agency experiences is that the team working on their account was very junior.

Margins are everything to a traditional agency, and these margins may well be more stretched now than ever before. In a 2025 survey, two in three marketing agency workers complained about their workload and the intensity of their work.  

A startup-friendly budget often means junior team members delivering the work, rather than the seniors who actually impressed you in the calls. This is a problem for obvious reasons: you came to an agency for experience and expertise, and you end up getting neither. 

So ask who will actually be working on your account. Ask about their experience. Go ahead and snoop around their LinkedIn profiles. This may seem like overkill, but agencies shouldn’t mind handing over this information. If they get shifty, consider this a red flag. 

Since we first started Growth Division, we’ve built up a trusted network of over 85 channel experts. They are all freelancers, consultants, and micro-agency owners – true experts who have been around the block and built up successful businesses based on their expertise. Our clients get to work with specialists in their field, but also people who really get what it means to run a business. 

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5. Understand the process (and check there is one) 

💡In short: Growth marketing won’t work if there isn’t a clear structure and process in place. 

There are different and valid approaches and frameworks for growth marketing, but there must always be a clear growth marketing process involved, and this process should include experimentation. 

This is a really important point to stress. The nature of fast-growing businesses means that really big shifts are important to chase, even if it means failed experiments along the way (this is normal). 

Without a smooth process, you risk something worse than an outright bad agency: an average one. The numbers go up every month, so you can’t say they aren’t delivering growth… but it’s safe, nice, incremental growth, and probably not the kind you came to a growth marketing agency for. 

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6. Look for specific experience within your niche

💡In short: Check whether this agency has worked with similar businesses to yours, whether that’s the same industry, revenue model, or audience.  

Let’s say you’re a supplement subscription business that just closed your series A round. I don’t necessarily think you should only work with agencies that have worked with other series A supplement subscription businesses, but you should look for some overlap. 

• That could be the type of product or business model (subscription, ecommerce, membership-based, SaaS)
• The audience (B2B, B2C)
• The industry (fintech, healthcare, edutech)
• Or the stage your business is at (pre-seed, series A)

Ask for an example of a previous client with an overlap of ideally three out of four of these categories (failing that, two needn’t be a dealbreaker – especially if there’s overlap in the problem they solved). This is especially important if you operate in a regulated industry. 

And don’t stop there. Once you’ve found those examples of overlap with past clients, go a little deeper. Ask the agency to talk through their approach and dig into the specifics. This is a great way to get insight into how they actually think and work. 

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7. Vet for a growth mindset

💡In short: Your agency should be talking about data, results, and experiments. 

‘Growth marketing’ is different to regular marketing, placing systemised experimentation and rapid learning at the core of the strategy. 

You should be able to get a sense from the wording on the agency’s website and what they say on their calls, of whether they truly have that ‘growth mindset’. 

Do they talk about testing, feedback and data, or are they more concerned with brand building, for example? Will they start delivering and learning quickly, or spend months perfecting strategy docs that need to be rewritten six months later?

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8. Explore the scope for pivoting

💡In short: If the best path to growth for your business is unknown, you need to understand how broad this agency can go to find it. 

When I write a proposal for a client, what I am really saying is ‘this is what I believe we should try first’. Because there’s no way of knowing quite what will work at the start of these projects, even after working with 130+ startups.

I’m suggesting a channel mix (based on my experience, our conversations, and my own research), but we are not committed to sticking with that mix. At the point we decide a channel doesn’t work for your business (after running structured experiments), we sub it out for a different one from the list of 20 traction channels. Our expert network of 80+ vetted freelancers and micro agencies means we’re ready to follow the data and take these new opportunities. 

More specialised growth marketing agencies are naturally less flexible. They might handle SEO, SEM, and social media ads, for example, and maybe this is exactly what you want. 

But if you’re looking to unlock a route to growth, without a clear picture or preference for how this looks, your agency needs to have flexibility to pivot that channel mix, and to do so quickly. 

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9. Understand the key results milestones & communication style

💡In short: Communication is everything to a client-agency relationship, so make sure you both understand what’s required of the other. 

Reporting and communication questions can easily become an afterthought. On paper, these things seem less important than results, relevant experience, and happy past clients.

But misalignment here can really get your relationship off to a bad start. There aren’t necessarily right or wrong answers, but you need to know what to expect. So don’t overlook the need to ask: 

• How the agency will communicate with you, and how often
• Who will be your main point of contact
• Whether this agency will be an extension of your team, or someone you meet with once a month 
• Where you will be able to see work, results, and past experiments
• How involved will you need to be in the day-to-day (what are the key sign-off milestones, etc) 

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10. Make sure you won’t become the bottleneck

💡In short: Get a sense of how much of your own time (or your team’s time) would need to be spent working with this agency, and if you have the capacity to take that on. 

Following on from the point above, you need to be realistic about how much time you have to commit to working with this growth marketing agency, and that this aligns with their process. 

Be clear on what you do or don’t need to sign off on, and make sure they are clear on exactly what skills and deliverables they’re going to cover, and what they’re expecting from you (and your team). When one person or team becomes the bottleneck, this can be frustrating and stressful for everyone involved. 

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11. Discuss the exit strategy

💡In short: Good agencies understand you won’t stay forever. They’ll be happy to talk to you about your next phase and help you offboard smoothly. 

You won’t work with a growth marketing agency forever. The best agencies are happy to help you prepare for their own exit from your very first conversation – whether that’s flexibility to move to a lower package as you start hiring in-house, or just a brilliant offboarding process that leaves you really well set up for your next phase.

One of the reasons we built our own growth marketing tool, GrowthEX, is that we wanted our clients to have a clear log of all the growth experiments we ran during our time together. Our own research showed us that growth leads struggle to keep these records, and we’d hate to see our clients going over old ground by accident.  

Final thoughts on choosing a growth marketing agency

These 11 tips cover everything that I would look for if I were choosing a growth marketing agency. It’s based on my experience of working with over 130 startups, and speaking with other founders who have had agency experiences – both good and bad. 

There are 11 tips here, but ultimately, I think it all comes down to: 

• Experience, expertise and process. Do they actually have the skills needed to get results for your business, and deliver the work you need? 
• Communication and expectations. Are they a fit for how you like to work, do you share the same values, and will you actually get on?  

And lastly: never worry about asking your prospective growth agency lots of questions! It’s in everyone’s best interest that all these things match up, and open conversations are the way to get to the bottom of that. 

‍If you are currently looking for a growth marketing agency, and you’d be interested to hear more about our process here at Growth Division, book a short call with one of our partners. No hard pitch – just an open chat about where you’re at right now!