Dillon: A Sustainable, No-Debt Path to Firm Expansion | Big 4 Transparency

Acquisition isn’t assimilation—it’s alignment.

Big 4 Transparency

By Dominic Piscopo, CPA

For CPA Trendlines

On the latest episode of The Big 4 Transparency Podcast, Marcus Dillon, founder and president of Dillon Business Advisors, offers a rare behind-the-scenes look at the art of accounting firm acquisitions and what happens after the deal closes. Having completed 15 M&A transactions, Dillon has quietly built a hybrid growth model that blends strategic purchasing with equally strategic divestitures, helping him scale while staying lean and focused.  

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Dillon’s approach flips conventional acquisition thinking on its head. Rather than simply absorbing the full book of business, Dillon’s team audits each client against their firm’s service model and values, and often sells off the clients who don’t fit. “We apply the 80/20 rule early in the due diligence phase,” he explains. “Twenty percent of the clients typically generate 80 percent of the revenue, and the rest are often where the frustration lies.” That filtering strategy, he says, allows for faster onboarding, better client service, and less internal chaos. 

Dillon, however, isn’t targeting mega-firms or private equity roll-ups. Instead, he’s finding opportunity in smaller legacy firms, often with outdated systems and annual-only service models. But that doesn’t bother him. “It’s like a box break,” he says, referencing the trading card phenomenon. “You buy the box, open it up, and see what value you can extract and grow.” His most recent acquisition, closed just days before tax season, brought in $600K in annual revenue and positioned the firm to grow past $4 million in 2025.