Repeat Purchase Economics for Supplement Brands
Supplements are a repeat-purchase category by nature. Customers don't buy one bottle of vitamins and disappear forever. Yet most Google Ads strategies optimise for first-order ROAS as if they did. Here's how to build campaigns that acquire customers worth acquiring.
The First-Order Trap
When your target ROAS is based on first-order revenue, you're essentially telling Google to find customers who will make one purchase. The algorithm optimises for exactly what you ask for.
The problem: customers who convert quickly on a first order often have lower lifetime value. They might be deal-seekers attracted by a discount, or impulse buyers who never reorder. Meanwhile, customers who take longer to convert but represent genuine interest often get deprioritised because they look expensive at the first-order level.
The Math Problem
Customer A: £30 first order, 2x ROAS, never reorders = £30 total value
Customer B: £30 first order, 1.5x ROAS, reorders 6 times = £210 total value
First-order ROAS optimisation picks Customer A every time. That's the trap.
Supplement Purchase Economics
Understanding the natural purchase patterns in supplements helps shape realistic expectations:
- Replenishment cycles: Most supplements last 30-90 days, creating natural reorder windows
- Efficacy realisation: Customers who feel benefits reorder at 3-4x the rate of those who don't
- Category expansion: Satisfied customers often add related products to subsequent orders
- Subscription conversion: 20-30% of happy customers convert to subscriptions within 3 orders
These patterns mean that the true value of a customer is rarely visible until 90-180 days after acquisition. Your measurement and bidding strategy needs to account for this lag.
Cohort Analysis Framework
Before adjusting bidding, you need data on how different acquisition cohorts actually perform:
30-Day Cohort Value
First order value only. This is what Google sees by default.
90-Day Cohort Value
First order plus any reorders within 90 days. Captures first replenishment cycle.
180-Day Cohort Value
Extended value window. Where subscription conversions start appearing.
365-Day Cohort Value
Annual customer value. The true measure of acquisition efficiency.
Segment this analysis by: acquisition campaign, entry product, first-order value tier, and discount usage. You'll find dramatic differences in repeat rates across segments.
Campaign Structure for Repeat Value
Structure campaigns to give different efficiency targets to products with different repeat profiles:
High-Repeat Entry Products
Products that historically lead to high repeat rates and subscription conversion.
Strategy: Accept lower first-order ROAS (even break-even) because the repeat revenue justifies it.
One-and-Done Products
Products with low repeat rates (seasonal items, condition-specific supplements).
Strategy: Require profitable first-order ROAS since there's no repeat revenue coming.
Gateway Products
Low-margin products that lead to high-margin repeat purchases.
Strategy: Optimise for customer acquisition, not first-order profit.
Bidding for Lifetime Value
Two approaches to incorporate repeat value into bidding:
Adjusted conversion values: Instead of passing the first-order value, pass a predicted lifetime value. If historical data shows customers from a particular campaign have 3x the average repeat rate, multiply their conversion value by a factor that reflects this.
Target ROAS adjustments: Set different target ROAS by campaign based on expected repeat rates. A campaign targeting high-intent search queries might get a 2x target, while a campaign targeting new-to-category browsers might get a 4x target (accepting lower first-order efficiency because repeat value will compensate).
The key is having enough historical data to make these adjustments with confidence. Start with conservative adjustments and refine as cohort data matures.
Measurement and Attribution
The technical challenge is attributing repeat purchases back to the original acquisition source:
- First-click attribution with extended windows: Credit all revenue from a customer to their original acquisition source
- Cohort-based reporting: Track customer cohorts by acquisition month and source
- Customer ID matching: Use enhanced conversions to link repeat purchases to original conversions
- LTV import: Periodically import updated customer LTV values to Google Ads
This requires integration between your ecommerce platform, CRM, and advertising platforms. The complexity is worthwhile because it transforms acquisition from a cost centre to a predictable growth engine.
The Bottom Line
Supplement brands that optimise for first-order ROAS are systematically undervaluing their best customers and overpaying for their worst. The brands winning in this space have built the infrastructure to see beyond the first transaction and bid for customers who will come back again and again.