GrowSurf

GrowSurf is the referral program platform Kevin Yun and Derek Shanahan bootstrapped from Los Angeles in 2018. It lets SaaS companies, fintech apps, and consumer products add a referral program — "refer a friend, get X months free" — in a day rather than months of custom development. The platform handles unique referral link generation, referral tracking through sign-up, reward fulfillment automation (trigger a Stripe coupon, add days to a subscription, or webhook to any custom system), and fraud detection. The company grew to $2M+ ARR with a small team by targeting growth-stage SaaS companies that had product-market fit and wanted to add a viral growth loop without building referral infrastructure from scratch. GrowSurf's JavaScript SDK and REST API made integration straightforward for technical teams, while a no-code dashboard let marketing teams manage the program without developer involvement. The referral program market is large but fragmented — GrowSurf carved out the B2B SaaS segment by focusing on Stripe integration and recurring subscription reward logic that consumer-focused referral tools handled poorly.