Referral program best practices?

We're exploring the idea of launching a referral program and wanted to get some insights from this community: Have you implemented a referral program? If so, what worked well (and what flopped)? What kind of incentives have driven the best results? (e.g., cash, discounts, extended free trials, extra resources, account credits, etc.) Did you build it in-house or use a tool? (Thinking about tools like Rewardful, ReferralCandy, etc.) Any unexpected challenges or things you wish you knew before launching? Would love to hear real-world examples of what’s working (or not working) for SaaS referrals. Appreciate any insights! 🚀