Some companies do not run out of opportunity.
They run out of courage to keep growing.
“If you focus relentlessly on return on ad spend, you will eventually efficient yourself out of business.”
— Brook Shepard, Founder, Mason Interactive
What you will get in 5 minutes: In this episode of The Proven Entrepreneur Show, Brook Shepard of Mason Interactive explains why sustainable business growth cannot come from cutting costs alone. You will see why founders, CEOs, and marketing leaders need to rethink ROAS, customer acquisition cost, experimentation, and the dangerous comfort of chasing efficiency while the business slowly stops growing.
Who Is Brook Shepard and Why His Advice Is Worth Your Time
Brook Shepard is the founder of Mason Interactive, a full-service advertising agency named after his 17-year-old son. He started the company around the time his son was born, and today Mason Interactive has offices in New York City, Charlotte, North Carolina, and Los Angeles after acquiring an agency there.
The agency works across search, social, programmatic advertising, TV, print, affiliate marketing, SEO, and email marketing. Brook shared that Mason Interactive has managed more than a billion dollars in assets, serves around 60 clients, and has 35 colleagues. The agency works with higher education institutions, emerging direct-to-consumer brands, and larger names such as Casio and Marimekko.
That matters because Brook is not speaking from theory. He has helped companies move from small monthly ad budgets to major profitable scale. His point is simple, and it is one many founders need to hear: sustainable business growth requires judgment, patience, and the discipline to look beyond surface-level efficiency.
Why Marketing Efficiency Can Quietly Kill Growth
Marketing efficiency can hurt a company when leaders treat low cost as the main definition of success. Brook’s warning is sharp because it goes against what many boards, investors, and operators push during uncertain markets.
When interest rates rise and outside capital becomes more demanding, companies often start chasing cleaner numbers. They want lower acquisition costs, stronger ROAS, and tighter budgets. Those goals are not wrong. The problem starts when efficiency becomes the whole strategy.
Brook explained that many funders and boards demand efficiency, and in digital advertising that usually turns into pressure around return on ad spend. But a company can become so focused on protecting ROAS that it stops feeding the top of the funnel. It looks disciplined for a while. Then growth slows.
His line lands because it is brutally practical: “You can’t cut your way to growth.” A founder can trim waste, remove bad spend, and improve margin. But there is a ceiling to cutting. There is no similar ceiling on growth when the business keeps learning how to acquire better customers.
Why ROAS Is Not the Whole Growth Marketing Story
ROAS is useful, but it becomes dangerous when leaders use it without understanding the full customer journey. Brook gave a clear example from a client that sold air fresheners.
Before working with Mason Interactive, the company focused heavily on getting new customers at the lowest possible cost. On paper, that looked smart. Lower acquisition cost usually feels like better marketing efficiency.
But the real profit was not in the first air freshener sale. It came from repeat filter purchases through a subscription model. That changed the entire math.
Brook explained that if the company could acquire fewer customers at $100 each, or acquire three times more customers at $150 each, the higher upfront cost could actually be more valuable. Why? Because more customers entered the subscription model sooner.
This is where sustainable business growth becomes a finance conversation, not only a marketing conversation. A cheaper customer is not always a better customer. A more expensive customer is not always inefficient. The real question is what that customer becomes over time.
The Better Framework: Quality, Quantity, and Customer Value
A stronger digital advertising strategy looks at lead quality, lead quantity, acquisition cost, and lifetime value together. Brook shared a simple way to think about this through a line from Dale Leatherwood: “I can get you lots of leads, I can get you good leads, I can get you cheap leads, pick any two.”
Cheap does not always mean profitable
A low-cost lead can look attractive in a dashboard and still produce weak revenue. Founders need to track what happens after the click, not only what happens before it.
More volume usually changes the economics
When a business wants more customers, cost often rises. That does not automatically mean the campaign is failing. It may mean the company has moved into a larger, more competitive part of the market.
Lifetime value changes the decision
If a customer buys repeatedly, subscribes, renews, or expands, the business can often afford a higher customer acquisition cost. That is where growth marketing becomes more mature.
The Expensive Mistake Smart Companies Keep Making
The expensive mistake is treating yesterday’s process as if it still guarantees tomorrow’s results. Brook said the industry changes so quickly that even a strong case study from a year ago may already be outdated.
That is uncomfortable for smart people because process feels safe. A company finds a tactic that works, builds a system around it, and then defends that system even after the market changes.
Brook pushed back against that kind of dogma. Mason Interactive’s view is not to simply do whatever the client asks. Their job is to give the client the best advice, then do what the client decides. That distinction matters.
He also warned against falling for pitches around secret data layers or hidden integrations. Meta and Google already hold massive audience intelligence. A third-party promise that there is a hidden switch behind the platform should be treated with caution.
For founders, the lesson is clear. Keep the process, but do not worship it. Keep the data, but do not hide behind it. Sustainable business growth needs both discipline and fresh thinking.
Key Takeaways from This Episode
- Efficiency is not the same as growth: A company can protect ROAS so aggressively that it stops creating future revenue.
- Customer acquisition cost needs context: A higher upfront cost may be smart if the customer has stronger lifetime value.
- Processes expire faster than leaders admit: What worked last year may already be weaker in today’s advertising platforms.
- There is no magic growth hack: Brook made it clear that real growth comes from repeated execution, not hidden buttons.
- Founders need full-funnel math: Looking only at cost per lead or ROAS can hide the real economics of the business.
- Trust comes from shared understanding: Brook emphasized consensus, patience, and learning how each client views their own metrics.
Frequently Asked Questions
What is sustainable business growth in digital advertising?
Sustainable business growth in digital advertising means acquiring customers in a way that supports long-term revenue, not just short-term efficiency. Brook Shepard explained that companies often chase low acquisition costs while missing the larger value of repeat purchases, subscriptions, or higher-quality customers.
Why is ROAS not enough to measure marketing success?
ROAS is not enough because it only shows part of the customer economics. A campaign can look less efficient upfront but create stronger long-term value if it brings in customers who repeat, renew, or subscribe.
What mistake do companies make with customer acquisition cost?
Companies often assume the lowest customer acquisition cost is always best. Brook’s air freshener example showed the opposite: paying more to acquire more customers made sense because the profit came later through subscription filter sales.
How should founders think about marketing efficiency?
Founders should treat marketing efficiency as one input, not the final answer. Efficiency matters, but when it becomes the only goal, the business may stop investing in the customer volume needed for growth.
Are growth hacks real in digital advertising?
Growth hacks rarely create durable business growth. Brook said there is no magic button in Meta ads that other agencies forgot to click. The real work is process, testing, patience, and consistent execution.
Why do advertising tactics stop working over time?
Advertising tactics stop working because platforms, audiences, competition, and economics change. Brook said even a strong case study from a year ago can become outdated, which is why companies need ongoing experimentation.
About Brook Shepard: Brook Shepard is the founder of Mason Interactive, a full-service advertising agency with offices in New York City, Charlotte, and Los Angeles. The agency works across digital advertising, SEO, email marketing, affiliate marketing, programmatic, TV, and creative services. Brook can also be found on LinkedIn under Brook Shepard.
Brook Shepard’s message is practical for any founder reviewing marketing numbers this week: do not let a clean ROAS report hide a shrinking growth engine. Look at the full customer journey, challenge old assumptions, and make sure efficiency is helping the business grow rather than slowly making it smaller. Listen to the full conversation with Brook Shepard on The Proven Entrepreneur Show.