He failed for 5 years. Then hit $20M ARR with 100% outbound. | Didi Gurfinkel, Founder of Datarails

Most B2B founders chase the biggest possible market, convinced that targeting a billion users beats serving a few thousand really well. Didi Gurfinkel spent five years proving this logic catastrophically wrong before discovering that Excel users aren't actually one market , they're dozens of distinct segments with radically different relationships to the tool everyone loves to hate.

Gurfinkel's breakthrough came from recognizing that finance professionals have a fundamentally different relationship with Excel than every other business user. While most departments treat Excel as a necessary evil, finance teams see it as core to their professional identity. As Gurfinkel puts it, "Finance people want to stay with Excel because it's more just a tool. This is part of their even skills. Right? The finance person, one of the things that they're proud of, I'm a Excel master."

This insight flipped conventional SaaS wisdom on its head. Instead of building a tool to replace Excel, Datarails built one that makes Excel more powerful. The distinction matters enormously for product positioning and sales strategy. When you're selling Excel replacement, you're fighting user behavior and professional identity. When you're selling Excel enhancement, you're working with both.

The finance-Excel relationship explains why so many productivity tools fail in finance departments. Outside finance, users actively want to escape Excel limitations. They call it "the second best option for anything," according to Gurfinkel. But finance professionals resist tools that threaten their Excel mastery because that mastery represents genuine professional skill and competitive advantage within their organizations.

Gurfinkel discovered this pattern only after burning through five years and multiple pivots trying to solve Excel problems for everyone. His original vision targeted the entire universe of Excel users , roughly a billion people across every business function. When advisors suggested focusing on a single use case, his reaction was dismissive: "Are you crazy? There are 1,000,000,000 Excel users. You want me to give up of of, I don't know, millions or hundreds of million of them?"

The focusing moment came when Gurfinkel analyzed which features actually drove customer satisfaction at his struggling 100k ARR company. Despite building a broad platform with multiple capabilities, customers consistently highlighted one specific function: data consolidation. "They take data from one system, export to excel, take it from another system, and when the data join together, now they have something that they couldn't see before," Gurfinkel explains. This consolidation capability became the foundation for everything that followed.

Data consolidation led directly to FP&A (Financial Planning & Analysis) as the target use case. FP&A represents the classic consolidation scenario , finance teams must gather data from multiple systems every month, combine it in Excel, and generate reports for management. It's repetitive, manual, and exactly the kind of workflow where Excel enhancement beats Excel replacement.

The focus on FP&A transformed Datarails' growth trajectory. The company scaled from that initial 100k ARR to over $20 million ARR primarily through outbound sales, proving that narrow market focus can generate massive business results. The success came not from expanding the addressable market but from deeply understanding one segment's actual workflow and identity.

Gurfinkel's experience suggests that market size calculations often mask fundamental misunderstandings about user behavior. A billion Excel users sounds like an enormous opportunity until you realize those users have completely different motivations, constraints, and relationships with the tool. Finance users who pride themselves on Excel mastery require different solutions than operations teams desperate to escape spreadsheet hell.

For founders evaluating focus versus breadth, Datarails offers a clear lesson: user count matters far less than user motivation. The path to product-market fit runs through understanding why people behave as they do, not just what they do. Finance professionals don't resist new tools because they're technologically conservative , they resist tools that threaten core professional competencies.

The next time you hear "there are a billion potential users," ask whether those users actually want the same thing. Gurfinkel spent five years learning that they don't.