Performance Marketing Scale Rule
Scale acquisition only while customer value stays above acquisition cost
- Difficulty
- Moderate
- Time to result
- ~weeks to results
- Steps
- 5
- Confidence
- 96%
The Performance Marketing Scale Rule turns customer acquisition into a measured allocation decision. Track spend and acquired customers by channel, calculate acquisition cost, and compare it with the value those customers generate over time. Yoni Assia described eToro as data-driven and performance-oriented: when the company spent a dollar and observed roughly three dollars coming back, it continued spending and scaling. He also compared acquisition cost with lifetime value rather than relying on cheap impressions alone. The mechanism is a feedback loop: test a channel, measure its unit economics, increase investment while the relationship remains attractive, and pull back when it no longer does. The output is controlled growth tied to observed returns rather than budget growth based on reach or intuition.
Origin
Extracted from The Foundr Podcast
Core principles
- 01Treat marketing as an investment with measurable returns
- 02Compare acquisition cost with customer lifetime value
- 03Scale channels that preserve positive unit economics
- 04Keep measuring because channel economics can change
How to run it
- 1
Separate the channels
Track acquisition spend and resulting customers by channel or campaign. Use a consistent attribution window so comparisons are meaningful.
Pro tip Begin with the channels where spend and customer actions can be linked most reliably.
Watch out Blended totals can conceal one channel subsidising another.
- 2
Measure acquisition cost
Divide attributable spend by the number of customers acquired. Include the costs needed to operate the campaign, not only media spend where material.
Pro tip Track acquisition cost over time and at different spend levels.
Watch out A low initial cost may rise as the easiest audience is exhausted.
- 3
Estimate customer value
Use observed revenue or contribution from acquired customers to estimate lifetime value. State the time horizon and assumptions explicitly.
Pro tip Prefer realised cohorts over optimistic forecasts when enough history exists.
Watch out Revenue is not the same as profit, and immature cohorts can overstate value.
- 4
Apply the scale rule
Increase spend when customer value remains sufficiently above acquisition cost for the business model. Reduce or stop investment when the relationship no longer supports the required return.
Pro tip Set the acceptable value-to-cost relationship before a campaign is scaled.
Watch out Do not treat eToro's reported return relationship as a universal threshold.
- 5
Revalidate at scale
Repeat the measurement as spend, audiences, and channels change. Confirm that higher volume has not weakened the economics.
Pro tip Compare recent cohorts with earlier cohorts at the same age.
Watch out Historical performance does not guarantee the next increment of spend will perform equally well.
In the wild
Assia said eToro began buying ads after its platform was operational and became highly data-driven in marketing. He described continuing to spend and push where a dollar of spend appeared to bring back three dollars, while monitoring acquisition cost against significantly higher lifetime value.
→ The company tied acquisition growth to observed channel economics and reported rapid early revenue growth.
A subscription company separates search and social campaigns, measures acquisition cost for each, and follows customer contribution by cohort. Search customers retain enough value to justify more spend, while the newest social cohort does not. The company raises the search budget and pauses social until it can test a better offer.
→ Budget moves toward the channel with stronger observed unit economics.
Common mistakes
Scaling from clicks instead of value
Traffic and registrations can increase while acquired customers fail to create enough value to cover their cost.
Treating one ratio as universal
The required return depends on margins, retention, cash flow, and the reliability of the lifetime-value estimate.
Assuming economics stay constant
Acquisition cost and customer quality can change as spend expands into broader audiences.
Is it for you?
Best for
It is best for businesses that can attribute customer acquisition and estimate value over time.
Not ideal for
It is not ideal when attribution is too weak or the observation period is too short to estimate customer value responsibly.
From the transcript
“any place where we spent a dollar and saw three dollars come back we just kept on spending and pushing”
“we are a very data driven and roi sort of performance marketing oriented”
“cost per acquisition and uh lifetime value is significantly higher”
From the episode
354: What Yoni Assia Of eToro Learned During Dinner with Warren Buffett
Yoni Assia