When you're deciding where to invest in growth, the choice often comes down to: get more traffic, or convert more of the traffic you already have?
The answer depends on your current conversion rate, traffic volume, and the cost of each approach.
The math for traffic growth
If you spend $10,000/month on paid ads to double traffic from 10,000 to 20,000 visitors at 2% CR and $99 ARPU:
- Additional conversions: 200/month
- Additional revenue: $19,800/month
- Cost: $10,000/month
- ROI: 98%
The math for CRO
If you spend $5,000 on a landing page redesign that lifts CR from 2% to 3.5%:
- Additional conversions: 150/month (10,000 visitors × 1.5% lift)
- Additional revenue: $14,850/month
- Cost: $5,000 one-time
- First-month ROI: 197% — and the improvement is permanent
When traffic growth wins
- Your conversion rate is already high (above 5%) — CR improvement becomes harder
- You have strong product-market fit but limited distribution
- Your paid channels have low CPCs in your target market
- You're trying to capture market share quickly before competition increases
When CRO wins
- Your current CR is below benchmark (under 2% for pricing page)
- Traffic is expensive in your vertical (CPCs > $5–10)
- You have enough traffic to run statistically valid tests (1,000+ visitors/month)
- You haven't run systematic CRO before — there are usually quick wins
The rule of thumb
If your CR is below 2%: invest in CRO first. If your CR is above 3%: invest in traffic once you can sustain volume. Between 2–3%: test both and measure cost per incremental conversion.
Use the Conversion Rate Calculator to model the exact revenue uplift of a CR improvement vs the equivalent traffic increase.