The Funnel Is Dead. Long Live the Flywheel.
HubSpot retired the marketing funnel in 2018 and replaced it with the flywheel model. The insight was simple: the funnel treats customers as an afterthought. Once someone converts, the funnel is done. But in SaaS, 70-80% of revenue comes from existing customers through retention and expansion. If your growth model ignores the biggest revenue source, it is broken.
The flywheel works because momentum compounds. A delighted customer leaves a G2 review. A prospect reads that review and books a demo. They become a customer, get great onboarding, and leave their own review. Each revolution of the flywheel requires less effort than the last because the energy from previous customers carries forward.
Measuring Flywheel Velocity
Track three things: the force applied (investment in each stage), the friction present (drop-off at each stage), and the speed of rotation (time from attraction to advocacy):
| Flywheel Stage | Force Metric | Friction Metric |
|---|---|---|
| Attract | Organic traffic, referral traffic | Bounce rate, content-to-lead rate |
| Engage | Demo-to-close rate, time to value | Sales cycle length, onboarding drop-off |
| Delight | NPS, CSAT, NRR | Support ticket volume, churn rate |
Where Flywheels Break Down
The flywheel breaks when one stage is weak. Most SaaS companies invest heavily in Attract (content marketing, paid ads) and Engage (sales team, demo process) but underinvest in Delight (onboarding, support, customer success). The result: high acquisition, high churn, and a flywheel that never builds momentum. Fix the weakest stage first.
Common questions about Flywheel Model
What is the difference between a flywheel and a funnel?
A funnel is linear — leads go in the top, customers come out the bottom, and the energy stops. A flywheel is circular — happy customers generate referrals, reviews, and expansions that create new leads, which become customers, which generate more momentum. The funnel treats customers as an output. The flywheel treats them as an input.
How do you build a SaaS flywheel?
Identify the three forces: attract (marketing brings in prospects), engage (sales and product convert them), delight (CS and product keep them successful). Then find the friction — where does momentum die? Long onboarding, poor support, no referral program. Remove friction and the flywheel spins faster.