Referral Program Economics: Reward Design, Viral Loops & Referral CAC

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Take Strideway's September referral numbers apart: who saw the prompt, who shared, how many invites each referrer sent and how many became paying subscribers.
• Compare Strideway's referred trial users with organic and paid ones: trial-to-paid, month-3 retention, the conversion lift and how many extra payers that lift means.
• Model Strideway's referral loop over six cycles: the viral coefficient, the new users each cycle brings, the running total and a chart of how fast it flattens.
• Add up everything Strideway's referral program costs, including rewards to cheaters and the tools, and compare the referral CAC with the paid-ads CAC.
• Compare five reward designs from Strideway's split test: how many paid referrals each brings, what the rewards cost and which design leaves the most value.
• Estimate the lifetime value of Strideway subscribers from each channel and compare LTV with CAC, to see what a referred subscriber is really worth.
• Work out how large Strideway's referral reward can be: the incremental value of a referral, the break-even reward, the maximum reward at a 3:1 LTV:CAC and the monthly budget.
• Screen a week of Strideway's paid referrals with two fraud rules, flag the suspicious ones with IF, OR and COUNTIFS and work out how much reward money to hold back.