Finding Growth Channels
Discover which acquisition channels will work for your product and learn to test them systematically before committing resources.
Growth Channels & PMF
Once you have retention working (evidence of PMF), you need to find scalable channels to acquire more of the right users. The best products find "channel-product fit"—where a specific channel works exceptionally well for their product.
"If you aren't acquiring customers for free, you're doing something wrong." — Brian Balfour
Channel Fundamentals
Understanding how growth channels work
The Law of Shitty Clickthroughs
Andrew Chen's "Law of Shitty Clickthroughs" states that all marketing channels degrade over time. What worked yesterday becomes saturated tomorrow. This means:
Early Adopter Advantage
First movers in a channel get the best results before it becomes crowded.
Constant Testing
You must continuously test new channels to find the next big opportunity.
Channel Economics
Every channel has key metrics you must understand:
The Channel Trap
Don't scale a channel before you have retention figured out. Pouring users into a leaky bucket just burns money. First prove retention, then scale acquisition.
The 19 Traction Channels
Overview of all major growth channels
Organic Channels
Word of Mouth / Viral
Users tell other users
SEO
Organic search traffic
Content Marketing
Blog, videos, podcasts
Social Media
Organic social presence
Community Building
Forums, Slack, Discord
Email Marketing
Newsletter, sequences
Paid Channels
Search Ads (SEM)
Google, Bing ads
Social Ads
Facebook, Instagram, TikTok, LinkedIn
Display Advertising
Banner ads, programmatic
Affiliate Marketing
Revenue share partnerships
Influencer Marketing
Paid creator partnerships
Sponsorships
Podcasts, newsletters, events
Offline & Sales Channels
Direct Sales
Outbound, cold outreach
Partnerships
Strategic alliances, integrations
Events & Trade Shows
Conferences, meetups
PR & Press
Media coverage, launches
Platform/App Stores
Marketplaces, directories
Engineering as Marketing
Free tools, calculators, APIs
The Bullseye Framework
A systematic approach to finding your channel
The Bullseye Framework (from "Traction" by Gabriel Weinberg) helps you systematically identify and test the right channels for your startup.
Core: Your #1 channel
Testing: 3 promising
Possibilities: All 19 channels
The Process
Brainstorm (Outer Ring)
For each of the 19 channels, brainstorm at least one idea for how you could use it. Don't dismiss any channel prematurely.
Rank (Middle Ring)
Rank channels by: (A) How likely is it to work? (B) Cost to test? (C) How many customers can it reach? Pick your top 3 to test.
Test (Moving to Inner Ring)
Run cheap tests on your top 3 channels. Goal: validate or invalidate each channel with minimal spend.
Focus (Inner Ring)
Double down on the channel that shows the best results. Become the best at this channel before testing others.
Channel Testing Playbook
How to validate channels quickly and cheaply
The Minimum Viable Test
Before committing significant resources, run a minimum viable test for each channel:
Content Marketing Test
Write 5 SEO-targeted articles. Measure traffic and conversions after 30-60 days.
Paid Ads Test
Run $500-1000 test on Facebook/Google. Test 3-5 ad variations. Measure CAC.
Cold Outreach Test
Send 100 personalized cold emails. Measure response and conversion rate.
Community Test
Post valuable content in 5 relevant communities. Measure engagement and signups.
Test Success Criteria
Before testing, define what "success" looks like:
- •CAC target: What's the max you can pay per customer?
- •Volume potential: Can this channel scale to 100+ customers/month?
- •Quality: Do customers from this channel retain well?
- •Sustainability: Can you maintain/improve performance over time?
Viral & Word of Mouth
Building growth into your product
The Viral Coefficient (K-Factor)
K = i × c
How many people does each user invite?
What % of invited users convert?
K > 1 means exponential growth. K = 0.5 means each user brings 0.5 new users.
Types of Virality
Inherent Virality
Product is better with others. Example: Slack, Zoom, multiplayer games.
Word of Mouth Virality
Product so good people tell others. Example: Apple, Tesla, exceptional experiences.
Incentivized Virality
Users get something for sharing. Example: Dropbox referrals, Robinhood.
Embedded Virality
Usage creates shareable output. Example: YouTube embeds, Canva designs.
Engineering Virality
Increase Invitations (i)
- • Make sharing easy/one-click
- • Prompt at moments of delight
- • Create shareable output
- • Add referral incentives
Increase Conversion (c)
- • Personal invites vs. generic
- • Show social proof
- • Reduce signup friction
- • Fast time-to-value
Channel Optimization
Maximizing performance once you find a channel
The Optimization Funnel
Once you have a working channel, optimize each stage of the funnel:
Identify your biggest drop-off and focus there. A 2x improvement at the bottleneck beats 10% improvements everywhere else.
Channel Stacking
Once your first channel is working, you can "stack" additional channels that complement it:
The 70/20/10 Rule
70% of resources on your proven channel (optimize and scale).
20% on adjacent, promising channels (expand what works).
10% on experimental channels (find the next big thing).
Practice Exercise
Apply the Bullseye Framework to your product:
- 1Brainstorm one idea for each of the 19 channels (outer ring)
- 2Rank by likelihood to work, cost to test, and potential reach
- 3Select your top 3 channels for testing (middle ring)
- 4Design a minimum viable test for each with clear success criteria
- 5Run tests and identify your winning channel (inner ring)