Many startups believe that once they achieve product–market fit, growth will naturally follow. In reality, that’s often where the trouble begins.

Model–market fit—sometimes called go-to-market (GTM) fit—is what determines whether a business can grow predictably, profitably, and at scale. It looks beyond whether customers want your product and focuses on whether your entire system for selling, delivering, and monetizing that product actually works.

In 2026, more startups are failing after early traction than before it. Not because demand disappears—but because the business model underneath the product can’t support growth.