Thomas Byrne has been on almost every side of an agency transaction.
He has founded a company and been bought out by his partner. He joined Periscopics as employee number eight, helped build its sales engine, and watched the agency grow to roughly 120 people before selling to Merkle. After the transaction, the business continued scaling to approximately 450 people.
Later, Thomas became CEO of RocketMill, an employee-owned agency that grew from roughly 70 people to 200 before selling to PMG.
Along the way, he also helped evaluate and acquire seven agencies as Merkle expanded across Europe.
That experience gave Thomas a perspective on M&A that goes well beyond valuation and financial diligence.
For him, the numbers matter. But agency value ultimately comes down to something harder to measure:
The people, the culture, and whether the organization can continue making good decisions when things get difficult.
Learning to Sell Before Learning M&A
Thomas did not begin his career in agencies.
He began in sales.
After university and a period working as a ski instructor, Thomas joined Pareto Law.
He had to sell.
The job involved enormous amounts of prospecting, rejection, and face-to-face meetings. Thomas estimates that over five years he met approximately 3,000 companies.
That repetition became his education in business.
He learned how people make decisions, how companies operate, and how much culture matters when employees are working in a demanding environment.
Eventually, he combined that sales experience with what he had learned about behavioral psychology and started his own business.
He raised £250,000 from a former client over dinner and built a company that eventually reached approximately 25 employees.
Then his partner decided to move to Australia.
Thomas did not want to go.
His partner bought him out.
It was Thomas's first transaction and the first time he had made meaningful money from the value of a business rather than from a salary.
That distinction would follow him throughout the rest of his career.
Joining Periscopics as Employee Number Eight
After the sale, Thomas became interested in digital marketing.
He started calling PPC agencies across the UK and asking them to hire him as a salesperson.
They mostly said no.
So Thomas built a website advertising himself as someone agencies could hire to sell PPC and ran paid search campaigns to it.
That eventually led to Periscopics.
Thomas joined as employee number eight and became the agency's first salesperson.
The agency was making an important transition: moving away from sales being exclusively founder-led and trying to turn business development into a repeatable organizational capability.
Thomas's philosophy was not to oversell.
Instead, he believed agency sales depended heavily on empathy, enthusiasm, trust, and managing client expectations correctly.
Over time, he built a sales team composed of specialists who understood the individual services the agency was selling. Clients were not simply meeting generic business development people. They were meeting experts capable of explaining the work.
Between 2009 and 2014, Thomas says Periscopics grew approximately 60% per year.
By the time the company sold, it had approximately 120 employees.
The Three-Month Sale to Merkle
Periscopics was not initially running a traditional sale process.
The leadership team was discussing strategy.
They had expanded from PPC into analytics and were considering where the company should go next. They considered moving further into CRM, expanding geographically, and even acquiring businesses themselves.
Around that time, Merkle acquired RKG in the United States.
Periscopics admired the company and saw similarities between RKG's position in the US and its own position in the UK.
One of the founders reached out to Merkle.
The message was essentially: if you want something like RKG in Europe, we should talk.
Merkle happened to be in London.
The companies connected, the fit became obvious, and approximately three months later Periscopics was sold.
For agency owners thinking about an eventual exit, the story is an important reminder:
The strongest transaction often begins with strategic fit rather than a decision to put the company up for sale.
Merkle did not simply need more agency revenue.
It wanted capabilities and a European platform that fit where it was going.
Periscopics could provide both.
Growth After the Deal
A sale is often treated like the finish line.
For Periscopics, it was another beginning.
Thomas says the agency grew from roughly 120 people at the time of the transaction to approximately 450 between 2015 and 2019.
And because the company continued performing, Merkle largely allowed the team to operate.
Thomas describes growth as a kind of panacea inside an acquiring organization.
If an acquired company is growing, delivering against expectations, and hitting its earnout, the parent company has fewer reasons to interfere.
If performance begins deteriorating, attention increases.
The Periscopics team exceeded its earnout targets and gained access to larger clients, more resources, and a wider set of capabilities after joining Merkle.
Eventually, Thomas moved from running sales into broader agency leadership.
His sales organization grew to approximately nine people, and he helped redesign pricing around an internal unit that allowed clients to purchase flexible combinations of capability rather than simply buying individual people.
The company was no longer growing through individual heroics.
It was building systems.
What Seven Acquisitions Taught Him About Due Diligence
After Merkle became part of Dentsu, Thomas gained access to a larger corporate development function and acquisition capital.
The strategy was roughly half organic growth and half acquisitions.
Thomas spent significant time meeting agency owners and evaluating businesses across Europe. The company ultimately acquired seven agencies during this period.
Seeing inside so many businesses accelerated his pattern recognition.
Two issues stood out.
The first was financial cleanliness.
Messy accounting was often an indication that other parts of the organization were messy too.
The second was founder dependency.
Thomas began evaluating not only what the company had achieved, but how the company actually made decisions.
Could the leadership team operate independently?
Did everything still need to run through the founder?
Was the founder's influence helping the business scale or preventing the organization from maturing?
Company size was not necessarily the answer.
Thomas encountered large companies that still behaved as though every decision required the founder.
That creates substantial risk for an acquirer.
An Agency Is Culture and Momentum
Thomas eventually reduced his view of an agency to two things:
Culture and momentum.
Traditional diligence tells you what the business has done.
Culture helps tell you what the business will do when its circumstances change.
That is why Thomas believes diligence should be much closer to 50% business and 50% people.
Imagine the company loses its three largest clients tomorrow.
What happens next?
Does the team panic?
Does everyone wait for the founder?
Or does the organization have enough trust, talent, and distributed accountability to respond?
Thomas believes those behaviors matter enormously because the same behaviors that took the company from where it was to where it is today are likely to influence whether it can reach the buyer's future expectations.
And you cannot understand all of that from a data room.
Sometimes you learn more by having an unscripted lunch or dinner with the team than by conducting another formal management interview.
When Two Strong Cultures Still Do Not Fit
Thomas also experienced what happens when two organizations have different philosophies about what creates agency value.
His perception was that Merkle came from a performance and data culture.
The team was the asset.
Great people could continue winning clients.
Dentsu came from a different tradition, with greater emphasis on the client relationship.
Neither approach was inherently wrong.
But they led to different decisions around talent, training, risk, management, and investment.
That experience reinforced something Thomas would later carry into his own acquisition philosophy:
Buying a good company does not automatically mean the two companies should operate the same way.
Integration becomes dangerous when the acquirer assumes its culture should simply replace the acquired company's culture.
The goal should be to understand what made each organization successful and intentionally determine what should remain, what should change, and what the combined organization should become.
Becoming CEO of the Agency He Once Wanted to Acquire
Thomas eventually left Merkle, spent a short period at Jellyfish, and then received another opportunity.
RocketMill.
Interestingly, Thomas had previously tried to acquire RocketMill while he was at Merkle.
Of all the agencies he evaluated, RocketMill was one of the companies he most wanted to buy.
The culture was strong.
The leadership team was strong.
And the agency had built an integrated offering spanning creative, media, experience, and analytics.
RocketMill had also transitioned into an employee ownership trust.
That appealed to Thomas because it aligned with one of his strongest beliefs: people are the primary asset inside an agency.
He joined as CEO in 2021.
Over the following period, RocketMill expanded its capabilities, developed internal technology, opened a London office, and grew from approximately 70 people to around 200.
Then the leadership team faced a new question.
What came next?
Deciding RocketMill Needed a Buyer
The original plan was not necessarily to sell RocketMill.
Thomas had explored the possibility of bringing other businesses into the employee-owned structure.
But the economics and tax structure made that path difficult.
At the same time, RocketMill was growing quickly enough that management could see a relatively narrow window in which a strategic transaction made sense.
The team eventually concluded that they needed to find a larger home for the business.
But the decision was not driven exclusively by valuation.
Thomas and the leadership team considered what an acquisition could provide employees.
Greater career headroom.
Access to larger global clients.
Protection against a potential market contraction.
And a stronger environment in which to navigate the coming changes created by AI.
Thomas wanted an American strategic buyer that could provide scale while allowing RocketMill to play an important role in European expansion.
PMG ultimately stood out.
The framework RocketMill used to evaluate the opportunity was simple:
Is there a strategic rationale?
Is there a cultural rationale?
Is there a financial rationale?
In that order.
PMG had a significant US business and wanted to expand in Europe. The businesses had complementary capabilities, compatible cultures, and eventually found a structure that worked financially.
RocketMill sold to PMG in December 2023.
The Deal Is About What Happens Next
Thomas Byrne has now watched two very different agencies scale and eventually sell to much larger strategic buyers.
Periscopics went from an independent performance agency to part of Merkle.
RocketMill went from employee ownership to PMG.
The transactions were different.
The lesson was remarkably similar.
Agency value is ultimately created by people capable of producing momentum.
Financial statements matter.
Client concentration matters.
Deal structure matters.
But buyers also have to understand what happens when the spreadsheet stops predicting reality.
Who makes the decisions?
Who keeps the clients?
Who develops the next leaders?
What does the team do when something goes wrong?
And can the cultures on either side of the transaction build something stronger together?
Those questions are much harder to answer than calculating a multiple.
They may also be the questions that matter most.
Listen to the Full Conversation
Listen to Thomas Byrne explain how he helped scale Periscopics before its sale to Merkle, what evaluating and acquiring seven agencies taught him about due diligence, how he led RocketMill from employee ownership through its sale to PMG, and why culture and people should sit at the center of agency M&A on the Agency Acquisitions & Exits Podcast.
