growth-model-designer

name	growth-model-designer
description	Design a quantitative growth model for your product. Use when someone says 'help me build a growth model', 'how should I think about our growth loops', 'I need a growth model spreadsheet', 'growth is slowing down', 'should we add PLG', 'help me map our acquisition channels', 'what are our growth loops', 'how do I model my business growth', or 'I want to understand how my product grows'. Walks through 8 stages from growth phase diagnosis through loop identification to spreadsheet modeling and outputs a Growth Model Blueprint.
type	decision
episodes	["casey-winters_","dan-hockenmaier","elena-verna","emily-kramer","bangaly-kaba"]
source_guests	["Casey Winters","Dan Hockenmaier","Elena Verna","Emily Kramer","Bangaly Kaba"]

Growth Model Designer

Walk a founder or growth lead through designing, diagnosing, and optimizing their company's growth model using frameworks from Casey Winters, Dan Hockenmaier, Elena Verna, Emily Kramer, and Bangaly Kaba on Lenny's Podcast.

When to Use

The user wants to understand how their product grows, identify growth loops, build a growth model, or diagnose why growth is stalling. They might say:

• "Help me map out our growth loops"
• "How should we think about our growth model?"
• "We're growing but I don't know why — help me understand our engine"
• "Growth is slowing down, help me figure out what to do"
• "Should we add PLG to our sales motion?"
• "I want to build a growth model spreadsheet for my startup"
• "Help me figure out our primary growth loop"

The Framework Stack

Run the company through these diagnostic stages in order. Each builds on the previous. Stop and discuss at each stage — don't rush through.

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Stage 1: Kindle vs. Fire — Where Are You?

From Casey Winters (CPO, Eventbrite; previously Pinterest, GrubHub) on Lenny's Podcast:

"I tend to separate growth into two phases. I call the first phase kindle strategies, these are those non-scalable hacks to get your early users. Fire strategies are the ones that drive scale, that's what you were mentioning, content loops, sales loops, viral loops, paid acquisition. And to me, the goal of your kindle strategies, these like non-scalable hacks, they only exist to unlock the fire strategies, to unlock the things that could take you to millions of users."

Ask the user:

1. How are you currently acquiring users? List every channel, tactic, and source.
2. Which of these are non-scalable (Kindle)? Founder outreach, manual demos, personal network, cold emails from the CEO.
3. Which are self-sustaining loops (Fire)? Content that ranks in search, users inviting users, paid ads reinvesting contribution margin.
4. Have you unlocked at least one Fire strategy? If not, the rest of this exercise is premature. Focus on finding product-market fit and building distribution into the product before it scales.

Casey's key insight on timing:

"It's once you unlock a fire strategy, that's when I think you think about hiring someone full time on growth to fully harness that new growth loop you've built. That could be a salesperson, if it's sales. It could be growth PM, if it's viral or you just see content. Or it could be a performance marketer if it's ads."

Decision gate: If the company is still in Kindle phase, advise them to focus on building growth loops into the product NOW — before product-market fit — so they have built-in distribution when ready. As Casey says:

"We're seeing founders who are thinking about building growth loops into their product before they find product market fit. It's not so that they can prematurely scale before they have product market fit. It's so that when they find product market fit, they have that built in distribution advantage to grow once they're ready."

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Stage 2: Fuel vs. Engine Diagnostic

From Emily Kramer (built marketing at Asana, Carta, Ticketfly; co-founder MKT1) on Lenny's Podcast:

"Forget the product marketing content partner, demand and growth, forget all of it, and just think of marketing as you need a fuel and you need an engine. Fuel is all the things that you're creating — the content, the words, the design. All the things that are going to add value. An engine is how you get it out to the right people."

Walk through the diagnostic:

1. What are your top-performing pieces of content? Best blog post, best landing page, best video, best template.
2. Do you know your positioning? Can you articulate: Who is this for? Why is it better? What are the benefits? How does it compare?
3. How are you distributing content? If the answer is "we shared it on social and it didn't go anywhere" — that's an engine problem.
4. What does the marketing-to-sales handoff look like? If it's a shared spreadsheet and manual outreach — engine problem.

Emily's decision framework:

"Where do you have the biggest challenge right now? Or where do you think if you did more, you would grow faster? Is it on the fuel side or is it on the engine side?"

Fuel examples: Website copy, blog posts, templates, webinar recordings, podcasts, positioning, case studies, calculators, tools.

Engine examples: Email segmentation and drip sequences, SEO technical infrastructure, paid ad campaigns, lifecycle marketing, HubSpot/CRM setup, distribution channels, community.

Some things are both: Community (generates content AND distributes it), SEO content (fuel is the article, engine is the keyword strategy and technical SEO).

Output: Classify the company's biggest constraint as Fuel, Engine, or Both. This determines what kind of growth investment to make next.

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Stage 3: Growth Loop Identification

From Elena Verna (growth at Amplitude, Miro, Dropbox, SurveyMonkey) on Lenny's Podcast:

"Anybody who thinks about growth in the funnel fashion versus understanding what the growth loops are is missing out on the ability to create sustainable growth engine. It's very important to think about action, reaction that generates another action and it's a self-contained flywheel that can spin."

The four types of growth loops (Casey Winters / Brian Balfour / Andrew Chen via Reforge, endorsed by Elena Verna):

1. Viral/Sharing Loops: Users invite other users as part of the product workflow. (Dropbox sharing files, Instagram tagging friends, Slack inviting teammates)
2. Content Loops: User or company-generated content attracts new users via search or social. (Pinterest pins indexed by Google, Miro's template gallery, user-generated reviews)
3. Paid Reinvestment Loops: Revenue from customers is reinvested in acquisition channels. (Contribution margin funds ads that acquire customers who generate more margin)
4. Sales Loops: Happy customers become references or case studies that help close new deals. Product-qualified leads from self-serve flow into sales pipeline.

Casey Winters on product-led sales as a unified loop:

"This concept is being dubbed product led sales. And it's this idea that you can unify self-service loops in a B2B business, which are typically driven by product, and your sales loops into one more complex giant loop that operates more efficiently and breaks down the silos."

For each loop the user identifies, ask:

• What action starts the loop?
• What output does it generate?
• How does that output feed back into another action?
• Is this loop currently spinning, or is it theoretical?
• What is the biggest bottleneck in this loop right now?

Elena Verna's real example of Dropbox's sharing loop:

"At Dropbox, over 50% of acquisition comes through sharing. So I load something into my Dropbox, maybe I need to send it out for signature. Maybe I need to just share this file to transfer it to somebody. Well, that recipient then is now aware of Dropbox... And the percentage of those recipients sign up to become Dropbox users, and that accounts for 50% of acquisition. That is a stable earned channel that nobody can compete with."

Bangaly Kaba's example of Instagram's layered growth loops:

"If you actually unpack the top of funnel for what worked at Instagram, there's certainly a component of it, which was our core component, which was invitations, where people inviting you and making sure that those invitations work... But another part that goes unspoken, still critical to this day was the celebrity partnerships... they also were getting picked up by the news and the media for all the stuff that's happening in the celebrity world, which then added onto this other growth level, which was SEO. And so you have not just the invites, but now you have the celebrities, now you have the SEO component. And then we would do a bunch of paid media on top of that."

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Stage 4: Earned vs. Rented Channels

From Elena Verna on Lenny's Podcast:

"When you're doing organic search or paid search, you're making Google richer. Great for Google. But all of that works on algorithm. An algorithm can giveth, but algorithm can also taketh away at any point. And you have no control because you don't own those channels."

Classify every current acquisition channel:

Channel	Type	Risk
SEO	Rented	Algorithm changes, AI eating search
Paid ads	Rented	Costs only go up, competition increases
Social ads	Rented	Platform algorithm controls distribution
User invites/sharing	Earned	Yours to keep, competitors can't buy it
User-generated content	Earned	Creates defensible content moat
Community/word of mouth	Earned	Deepest moat, hardest to replicate
Referral programs	Earned	Controlled by you, powered by users

Elena's imperative:

"Focusing on these earned channels that you own becomes the outmost priority. And if you don't have them on your growth roadmap, you are going to be in some really big trouble over the next year to two years because your cost of acquisition is only going to go up."

Ask: What percentage of your acquisition comes from earned channels vs. rented channels? If earned is below 30%, flag this as a strategic vulnerability.

Elena on what earned channels look like in practice:

"I'm really big on creating a growth loop out of user generated content. I think with everything that is happening with AI and SEO at the moment, your biggest claim to fame on content strategy will be harnessing user generated content. Whether it's user generated templates, whether it's user generated case studies, reviews, whatever it is."

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Stage 5: Growth Model Spreadsheet

From Dan Hockenmaier (Director of Growth at Thumbtack, Head of Strategy & Analytics at Faire, built 20-30 growth models at Basis One) on Lenny's Podcast:

"I think about a growth model as the analytical representation of how the business grows and it's typically built in a spreadsheet which has a really nice feature of being very hard to fake. You can talk about a business conceptually, but when you actually have to get it to line up and link in a model, it's very hard to not force yourself to understand how the business works."

Building blocks by business type:

SaaS businesses — three components:

1. Acquisition channels: Traffic/spend per channel, conversion rates
2. Retention: Activation rate, monthly retention curve / survival rates
3. Monetization: Monthly or annual fee per customer

Transactional businesses — add: 4. Transactions per retained customer per month, average order value (AOV) 5. Unit economics / COGS per transaction

Marketplaces — add: 6. Supply acquisition and retention 7. Demand-supply interaction dynamics

Dan's critical insight on making it non-linear:

"Where it gets really interesting is when you start making it non-linear. So the most basic example of this would be virality. Your existing customers are referring new customers and those go on to refer new customers. And similarly with paid marketing, as you generate contribution margin, you can reinvest that. If you link those two up explicitly, it makes it really clear why thinking about something like payback period is a much better measure of paid marketing performance than LTV to CAC."

Dan on 50% of the value being the building process:

"50% of the value you get from it is simply building the model. It forces you to understand it and then you get this artifact which you can use to understand how to weigh different opportunities. Importantly it is not a forecasting tool. It is a great tool for opportunity assessment for the business."

The Thumbtack revelation — when the model changed everything:

"The first one I built was at Thumbtack, and it made it so immediately obvious that we were exceptionally sensitive to the repeat rate of new customers... the rate at which we cross-sold them into other categories made all the difference because it radically changed the LTV of that customer, which then fed back into how much we could go pay to acquire new customers. Building this model helped us internalize that we needed to shift a bunch of resources from top of funnel to deeper in the stack."

Help the user sketch their model:

1. List their acquisition channels and estimated volume/conversion
2. Estimate activation rate and monthly retention curve
3. Define their monetization (subscription, transaction, usage)
4. Identify where loops connect (virality coefficient, reinvestment rate)
5. Ask: "If you could move retention by 5%, or conversion by 20%, which matters more?" Run the scenario.

Dan on why retention always surprises people:

"Your growth is much more sensitive to customer retention than you can ever intuit because there's a lot of interaction between having a healthy retained customer base and everything else you care about, which is the rate at which they're referring new customers, generating content, generating contribution margin. A smaller percentage gain on retention is often much more valuable than making a bigger change in some other area."

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Stage 6: Loop Lifecycle & S-Curve Awareness

From Elena Verna on Lenny's Podcast:

"If you over-optimize the same thing over and over again, it has minimal returns, and some growth models have very limited time spans. Some of them are huge. The sharing loop at Dropbox, it's 17 years in the making and it's still firing. But that's very much an anomaly. Most of growth loops spin out their ability to produce meaningful results for you within the first five to six to seven years."

Elena's operating rules for loop lifecycle:

"Every 18 months you need to introduce something new... And every five years or so, you for sure need new channel, new growth loops, new tactics, new engines to power your growth engine."

"I try to focus 20 to 25% of growth team's time annually — not every given sprint or not every given quarter, but annually — to introduce a new growth loop, or to introduce a new channel, or to introduce something new that can potentially bring us additional oomph to our growth engine."

Elena on layering growth models (PLG + Sales + Marketing):

"Not overlaying every single way that you can grow through product, through marketing and through sales as an evolution is a huge mistake. Continuously overlaying those different growth models — product-led growth, marketing-led growth, sales-led growth — and introducing it into this ecosystem constantly is what really separates companies that can continue growing for long periods of time versus the ones that see a really big blip and then it starts to slow down."

Ask the user:

1. How old is your primary growth loop? If 3+ years, what's your next one?
2. What percentage of growth team time goes to exploring new loops vs. optimizing existing ones? (Target: 20-25% on new)
3. Are you layering multiple growth models (PLG + sales + marketing), or dependent on one?
4. What's the next growth model you could overlay?

Miro case study from Elena:

"Mirrorverse, which is a user-generated content library of all of the Miro boards that people create, it took us probably 18 months until we started putting metrics expectations on it. Before that, it was a thing that we were testing. And then it started taking off as both engagement engine as well as acquisition engine."

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Stage 7: Adjacent User Assessment

From Bangaly Kaba (early growth PM at Facebook, Head of Growth at Instagram, VP Product at Instacart, now YouTube) on Lenny's Podcast:

"This was something that came out of my time at Instagram. We grew so fast that the people who were using Instagram in February were completely different than people who were using it the following October. When I joined, we were at 440 million monthly actives. At the end of that year we were at 636 million, grew like 47% that year. When we talked to women in the US in their 30s, they're like, 'Why would I have an Instagram? I have a Facebook account.' And then a year later it's like, 'Of course I use Instagram. Instagram is my everything.'"

Bangaly's diagnostic questions:

1. Who is your current core user? What motivates them? Why do they use the product?
2. Who is your adjacent user? The person just outside your current user circle who could use the product but for some reason it doesn't work for them.
3. What signals in the data show adjacent users arriving? Bangaly's key signal: "You start seeing cohort curves decline. Nothing's changing in the product, but just the understanding of how the product should work is different."
4. Have you used the product as the adjacent user? Create a fresh account, use a different device, see what breaks.

Bangaly on why this matters for every company, not just hypergrowth:

"I think it's essential. It's mandatory for hypergrowth. I think it's very helpful if you have a product or a company that is not growing what you want it to be. Really talking to who is just outside of your current user base, who's coming to your product and looking around and not buying, and understanding what are their needs."

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Stage 8: PLG Readiness Check (if applicable)

From Elena Verna on Lenny's Podcast:

"If you have any product-led components where product is responsible for acquisition, activation, monetization or retention, that's where growth comes in."

Quick PLG assessment — does the company have:

• A free vehicle (free tier, free trial, open source, interactive demo)
• Quick time to value (warm start, sample data, templates)
• Self-checkout flow (buy without talking to anyone)
• Data foundation (product analytics, behavioral data, experimentation)
• Simple pricing (no quote-request required)

Elena on when to overlay PLG on sales:

"If you're starting with self-serve monetization, growth hire should be frankly first before sales. Your sales are going to be more opportunistic in nature. If you're a sales-led company, go ahead, hire sales, wait for growth until you are ready to overlay product-led growth on top of your sales motion."

Elena's warning on timing:

"Don't hire growth teams until you actually can start running experiments on your user base, which means that you have volume of users that you can learn from and optimize and innovate on, and that first wave of growth has to be founder led."

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Anti-Pattern Check

Before finalizing the growth plan, run it through Elena Verna's 10 things that never work:

1. Hiring a growth team too soon. Founder-led growth must come first.
2. Hiring a shiny growth head to fix a declining business. Growth can amplify good PMF, not fix bad PMF.
3. Rebrands/redesigns as growth levers. Never once produced meaningful performance results.
4. Testing everything. "If every single one of your initiatives is an experiment, that's a problem. It's almost like a paralyzing disease."
5. Treating every problem as unique. "Your problem has been solved by somebody. Go find those patterns."
6. Growth teams owning paid/SEO/social. Priority should be earned channels.
7. Not overlaying multiple growth models. "Most growth loops spin out within five to seven years."
8. Color optimizations. "A blue is a blue is a blue."
9. One-email wonders. A single email will never produce meaningful lift.
10. Obsessing over removing friction. "Simplify onboarding" is an action, not a problem statement.

Ask: Does your current growth plan contain any of these anti-patterns? If so, flag and redirect.

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Output

After running all eight stages, deliver:

1. Growth Loop Map

Visual or textual map of every growth loop currently operating or planned. For each loop: the trigger action, the output, the feedback mechanism, and current status (spinning / theoretical / stalled).

2. Primary Loop Identification

Which loop is the main engine today? How healthy is it? What's the biggest bottleneck?

3. Fuel vs. Engine Diagnosis

Where is the constraint — creating valuable content/positioning, or distributing it effectively?

4. Earned vs. Rented Channel Mix

Percentage breakdown. If over-indexed on rented channels, specific recommendations for earned channel development.

5. Growth Model Structure

The building blocks for their spreadsheet model:

• Acquisition channels and conversion assumptions
• Retention curve shape
• Monetization model
• Non-linear connections (virality coefficient, reinvestment rate)
• The one scenario that would change everything (a la Thumbtack's repeat rate discovery)

6. Loop Lifecycle Assessment

Age of each loop, expected remaining runway, what's in the pipeline for the next S-curve.

7. Adjacent User Profile

Who the next wave of users is, what's broken for them, and what to build to capture them.

8. Optimization Plan

Prioritized list of growth investments for the next quarter, classified using the Race Car Framework:

• Engines (loops): Long-term compounding growth drivers
• Fuel: Resources that amplify the engine (paid spend, sales headcount)
• Turbo boosts: One-time high-impact events (launches, PR, conferences)
• Lubricant: Ongoing optimizations (A/B testing, conversion rate improvements)

Format the final output as a Growth Model Blueprint:

GROWTH MODEL BLUEPRINT
==================================
Company: [name]
Date: [today]
Business Type: [SaaS / Transactional / Marketplace / PLG / Hybrid]

1. Growth Phase: [Kindle / Fire / Transitioning]
   → [1-sentence assessment of where they are]

2. Growth Loops (Active):
   - [Loop name]: [trigger] → [output] → [feedback] | Status: [spinning / stalled]
   - [Loop name]: [trigger] → [output] → [feedback] | Status: [spinning / stalled]

3. Growth Loops (Planned / Needed):
   - [Loop name]: [what it would look like] | Timeline: [estimate]

4. Primary Engine: [which loop drives the most growth today]
   - Biggest bottleneck: [specific constraint]
   - Sensitivity: [what small change would have outsized impact]

5. Fuel vs. Engine: [Fuel-constrained / Engine-constrained / Both]
   → [1-sentence diagnosis]

6. Channel Mix:
   - Earned: [X]% — [list channels]
   - Rented: [X]% — [list channels]
   → Risk level: [Low / Medium / High]

7. Growth Model Spreadsheet Inputs:
   - Acquisition: [channels, volumes, conversion rates]
   - Retention: [activation rate, monthly retention curve]
   - Monetization: [model, ARPU/AOV, unit economics]
   - Non-linear links: [virality coefficient, reinvestment rate]
   - Critical scenario: [the one variable that changes everything]

8. Loop Lifecycle:
   - [Loop]: [age] years old — [healthy / plateauing / declining]
   - Next loop investment: [what and when]

9. Adjacent User:
   - Current core user: [profile]
   - Adjacent user: [profile]
   - What's broken for them: [specifics]

10. Race Car Plan (Next Quarter):
    - Engines: [growth loops to build/strengthen]
    - Fuel: [spend, headcount to add]
    - Turbo Boosts: [one-time events]
    - Lubricant: [optimizations to run]

ANTI-PATTERN FLAGS: [any from Elena's list that apply]

HONEST ASSESSMENT: [Build the model / Fix PMF first / Layer a new loop / Shift from rented to earned]
[2-3 sentence direct assessment of the company's growth position and what to do next]

Be direct. If they need to fix product-market fit before worrying about growth models, say so. If their entire acquisition depends on rented channels, sound the alarm. If they have one loop that is clearly the engine and they are under-investing in it, name it. Elena Verna's standard applies: "Growth can amplify great product-market fit and growth can help you grow faster once you are already growing. But if you are slowing down and you have issues with either your go-to-market strategy or your core product strategy, growth is going to be absolutely helpless."

Related Skills

• pmf-evaluator — Confirm PMF before designing growth loops; loops amplify fit, they do not create it
• growth-loops-masterclass — Learn loop theory before building the quantitative model; the masterclass teaches the concepts, this skill builds the spreadsheet
• network-effects-workshop — If your loop involves network effects, stress-test whether those effects are real using Hamilton Helmer's materiality test
• activation-masterclass — Your activation rate is a key input to this model; define the activation event first so the model uses real numbers

Related Frameworks

• race-car-framework.md — The Engine/Fuel/Turbo Boost/Lubricant classification used in the optimization plan output
• growth-model-spreadsheet.md — Dan Hockenmaier's guide to building the non-linear growth model spreadsheet used in Stage 5
• adjacent-user-theory.md — Bangaly Kaba's framework for identifying the next wave of users, used in Stage 7
• fuel-vs-engine.md — Emily Kramer's diagnostic for whether the constraint is content creation or distribution, used in Stage 2
• elena-verna-10-growth-tactics.md — The anti-pattern checklist used to validate the growth plan before finalizing
• north-star-translation-layer.md — Connecting growth model metrics to the company's north star metric
• elena-verna-pls-bridge.md — Bridge the gap between self-serve usage and enterprise contracts without breaking the product experience
• plg-funnel-audit.md — Walk through your product as a new user to find the biggest leverage point across acquisition, activation, conversion, and retention
• wise-word-of-mouth.md — Engineer word-of-mouth by making the product 10x better on the dimensions customers actually talk about
• customer-led-growth.md — Map your customer's journey through struggle, evaluation, and growth phases to find the growth bottleneck
• organic-first-feature-validation.md — Validate organic pull before scaling growth investment; never add fuel to a broken engine
• idea-maze-for-product-strategy.md — Map the competitive landscape to identify which growth corridors remain open

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Source Transcripts

Guest	Episode	Key Frameworks
Casey Winters	episodes/casey-winters_/transcript.md	Kindle vs. Fire strategies, four growth loop types, product-led sales
Dan Hockenmaier	episodes/dan-hockenmaier/transcript.md	Growth model spreadsheet, non-linearity, retention sensitivity, marketplace metrics
Elena Verna	episodes/elena-verna/transcript.md	10 anti-patterns, earned vs. rented channels, loop lifecycle, growth loop overlay, PLG readiness
Emily Kramer	episodes/emily-kramer/transcript.md	Fuel vs. Engine diagnostic, pi-shaped marketers
Bangaly Kaba	episodes/bangaly-kaba/transcript.md	Adjacent User Theory, Instagram layered growth loops, understand work
Lenny Rachitsky & Dan Hockenmaier	Referenced across episodes	Race Car Growth Framework (Engine, Fuel, Turbo Boost, Lubricant)