DM9: Growth engineering: referrals, sharing and lifecycle messages
Growth loops, activation and retention
🎯You'll be able to
Describe a growth loop, define activation for a product, and explain why retention comes before acquisition.
🏠The everyday picture
A good sweet shop doesn't only advertise. Each box it sells goes to a family gathering, guests ask where it came from, and some of them become customers who buy boxes for their own gatherings.
📘What it really is
- A funnel (DM6) is a one-way path. A growth loop feeds its output back in: a customer's action brings new customers.
- Referral loop: buyer → invites a friend → friend buys → invites another.
- Content loop: customers' reviews and photos → more search visits (DM2) → more buyers → more reviews.
-
Sharing loop: a shared wishlist or gift link → visitors → buyers.
-
Activation is the first moment a new customer gets real value: for MittiMart, a first order delivered intact and used. Define it as an event you can measure (for example, a second visit after delivery or a review).
-
Retention first: a leaky bucket can't be filled. If few customers come back (DM6 cohorts), bringing more of them in mostly costs money.
-
Measure loops with cohorts and experiments: how many new customers each cohort brings, and whether a feature changes that (DM7).
- Fit the product: loops work when the product is worth recommending. A referral bonus can't fix a product people don't like.
📝A worked example
Input: MittiMart's possible loops.
| Loop | Action | Output | Measure |
|---|---|---|---|
| Referral | Buyer shares a ₹100-off link | Friend's first order | Referred first orders per 100 buyers |
| Reviews | Buyer adds a photo review | Richer product pages | Organic visits to reviewed products |
| Gifting | Buyer sends a festival gift | Recipient sees the brand | Recipients who later order |
Expected output: one loop chosen for the capstone design notes, with its measure and the experiment that would test it.
🌍Where it's used
- Payment apps grew through invite rewards and paying friends.
- Marketplaces grow through sellers who bring their own customers.
- Content platforms grow through creators sharing their work.
📝Case scenario
A meal-kit start-up spent heavily on ads and referral bonuses. Cohorts showed 70% of customers didn't order a second time because of late deliveries. It paused referral bonuses, fixed delivery slots, and restarted the programme months later, when referred customers stayed.
🖱️Try it
Pick an app you use that grew partly by itself. Draw its loop in four steps: action, output, how the output brings someone new, and what that person does. Success: the loop returns to its start.
⚠️Common mistakes
- Buying growth before fixing retention. Sign: rising acquisition costs and flat repeat orders. Fix: improve retention first.
- Vague activation. Sign: "engaged users". Fix: one measurable event that reflects real value.
- Loops without measurement. Sign: "the referral programme is working" with no cohort. Fix: measure referred customers per cohort.
🛠️For your project
Your capstone's design notes describe one MittiMart growth loop with its measure.
✅Quick check
What's the difference between a funnel and a loop?
Show the answer
A funnel is one-way; a loop feeds its output back to bring new customers.
Why fix retention before spending on acquisition?
Show the answer
New customers who don't return mostly cost money; a leaky bucket can't be filled.