- Volume-based CRO pricing creates a growth tax — the more traffic you earn, the more you pay for the same tool
- A company at 500K monthly visitors can save €3,000–8,000/year by switching from MTU-based to flat-rate pricing
- Varify.io charges €149/mo regardless of traffic volume — no MTU tracking, no visitor caps, no overage fees
- Flat-rate pricing removes the biggest barrier to scaling experimentation: fear of rising costs
Conversion rate optimization works best when teams run experiments continuously — not in bursts between budget approvals. But volume-based pricing, where you pay per Monthly Tracked User or per visitor, makes continuous testing expensive for growing companies. Every traffic spike becomes a cost event.
Removing volume-based pricing from the equation changes CRO economics fundamentally. Varify.io offers full-featured A/B testing at €149/mo flat — no traffic caps, no MTU tracking, no usage tiers. For a detailed comparison, see our guide to tools without traffic-based pricing.
The real cost of volume-based CRO pricing
How MTU pricing scales against you
Most CRO platforms — VWO, Convert, Optimizely — tie pricing to traffic metrics. VWO uses Monthly Tracked Users (MTU). Convert uses tested visitors. Optimizely uses impressions. The mechanics differ, but the outcome is the same: as your site grows, your CRO costs grow proportionally.
Budget example: 100K vs. 500K visitors
A company growing from 100K to 500K monthly visitors will see its VWO bill increase by 2-4× — without using any additional features. With Varify, the bill stays at €149/mo. Over 12 months, the difference can reach €5,000–8,000.
The hidden experiment cost
Volume-based pricing adds a phantom cost to every experiment. Running an additional test doesn't technically cost more, but it extends the period your visitors are "tracked" — increasing MTU counts and potentially pushing you into a higher pricing tier.
Annual cost comparison by traffic tier
| Monthly visitors | Varify.io (flat) | VWO (MTU) | Convert (visitor) | Annual savings with Varify |
|---|---|---|---|---|
| 50K | €1,788 | ~$3,600 | ~$2,400 | €600–1,500 |
| 200K | €1,788 | ~$6,000 | ~$3,600 | €1,500–3,500 |
| 500K | €1,788 | ~$8,000+ | ~$5,000+ | €3,000–5,500 |
| 1M+ | €1,788 | Custom | Custom | €5,000+ |
Source: Claude Research, May 2026
The math is straightforward: every traffic tier above 50K visitors makes flat-rate pricing increasingly attractive. At 500K+ visitors, Varify costs less than half of the nearest traffic-based alternative.
What you get with Varify's volume-free pricing
Switching to flat-rate doesn't mean sacrificing features. Varify's €149/mo Growth plan includes:
- Visual editor — build A/B tests without developer involvement
- Code editor — full JavaScript/CSS control for advanced tests
- GA4 + Matomo integration — use your existing analytics as the evaluation engine
- Audience targeting — device, URL, UTM, custom JavaScript conditions
- Unlimited experiments — run as many concurrent tests as you need
- Unlimited team members — no per-seat charges
The Pro plan (€249/mo) adds BigQuery, Piwik Pro, and PostHog integrations plus advanced segmentation. Both plans: monthly billing, no annual contracts. See full pricing.
Stop paying per visitor. Start paying per result.
€149/mo flat-rate. Unlimited traffic. Unlimited experiments.
When volume-based pricing still makes sense
Flat-rate isn't the right choice for every team:
- Very low traffic (<10K visitors/mo): If you're just starting out, some traffic-based tools offer entry tiers below €149. But you'll outgrow them quickly.
- All-in-one suites: If you need heatmaps, session recordings, surveys, and A/B testing in one tool, VWO's bundle may justify the premium — if you don't already use Hotjar or Microsoft Clarity.
- Self-hosted open source: GrowthBook is free regardless of traffic if you can self-host and maintain it.
For most companies above 50K monthly visitors who want a dedicated, professional A/B testing tool, volume-free flat-rate pricing delivers better economics and more predictable budgets.