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Discover what makes us different
Our average client sees a 35% lift in conversion rate across 150+ CRO projects.
500+ tests run across landing pages, checkouts and lead capture forms.
Every change is backed by analytics, heatmaps and real session data.
Certified VWO partners running enterprise-grade experimentation programmes.
Here's what sets us apart from the competition
Find answers to common questions
Prebo integrates CRO work with GA4, Google Tag Manager, server-side tracking, and common ecommerce platforms like Shopify and WordPress to ensure accurate event capture and attribution. We also set up ETL or data-layer solutions where needed so test results feed into a single source of truth for decision making.
Common experiments include A/B tests, multivariate tests, funnel experiments, UX and checkout performance optimizations, and technical fixes that reduce friction. Test duration depends on traffic volume and required statistical power but typically ranges from several weeks to a few months per experiment cycle.
We prioritise revenue-per-visitor, conversion rate, average order value, customer acquisition cost (CAC), lifetime value (LTV), and marketing efficiency ratio (MER), alongside statistical significance for experiments. Clean attribution and centralized data pipelines ensure those metrics reflect true business impact rather than platform-reported figures.
CRO is designed to improve conversion efficiency and attribution accuracy, which can increase revenue and profitability when combined with product-market fit and adequate traffic. Outcomes vary by business and depend on test quality, funnel issues identified, and downstream economics, so results are not assured and are measured against revenue-focused KPIs rather than vanity metrics.
CRO is the systematic process of improving a website or funnel to increase revenue per visitor. Prebo Digital uses a technical-first, analytics-driven approach with hypothesis-driven experiments, server-side tracking, and funnel-level optimization focused on measurable revenue outcomes.
In This Article
Outcomes-first scoring
Measurement-first approach
Structured 5-stage roadmap
Choosing a growth marketing retainer service is less about selecting a list of deliverables and more about selecting a structured growth partner that aligns with your unit economics: CAC, LTV, MER and profitability. This guide explains how to evaluate retainers using measurable criteria, with US-focused examples and tracking-first considerations. Use this when you need a partner designed to increase revenue, not just traffic.
Define the outcomes you want the retainer to impact. Typical outcomes include decreasing CAC by X%, increasing monthly recurring revenue by $Y, or improving funnel conversion rates across TOF → MOF → BOF. Spell out acceptable ranges-e.g., reduce CAC by 10-25% within 6-12 months is a reasonable estimate depending on channel mix and historical performance. These are estimates and depend on channel spend, creative quality, and product margins.
Assess each agency or retainer across: 1) Measurement & attribution, 2) Growth strategy and experimentation, and 3) Technical implementation and automation. For a practical check, ask for a sample monthly reporting pack, an experiment roadmap, and an architecture diagram for tracking.
A simple conversion tracking flow a retainer should propose:
If you want to compare approaches, see Prebo Digital's overview of services here and the agency's homepage for examples of technical-first work here.
Note: In the US, privacy and consent (e.g., CCPA) affect client-side signal availability. A retainer that prioritizes server-side tracking and clean ETL will reduce attribution gaps.
The most practical retainers map work to a five-stage cadence: Strategy → Build → Test → Scale → Report. When vetting proposals, ensure each stage lists concrete outputs (example: GA4 + server container, 8 A/B tests per quarter, creative test matrix, and MER-driven scaling rules).
| Funnel Stage | Primary Metrics | Typical Tactics |
|---|---|---|
| TOF (Top of Funnel) | Impressions, CTR, New Users | Paid social, prospecting search, creative tests |
| MOF (Middle of Funnel) | Add-to-cart, email signups, remarketing lists | Email flows, dynamic retargeting, CRO experiments |
| BOF (Bottom of Funnel) | Conversion rate, AOV, revenue | Checkout optimization, server-side reconciliation |
Retainer models vary: fixed-scope monthly retainers, time-and-materials, or performance-linked fees. For predictable scaling, many US founders prefer a hybrid: a base monthly retainer for strategy and technical work plus a variable performance band tied to defined revenue metrics. Ask for clear inclusions and exclusions-e.g., whether creative production, ad spend, or third-party tool costs are covered.
Ask for a case study that shows before/after metrics focusing on revenue and attribution clarity. Request sample architecture diagrams and a brief technical audit (even a 30-minute discovery call can reveal depth). If your store runs on Shopify or WooCommerce, ensure the retainer has direct experience with those platforms and common stacks like Stripe, Klaviyo, and GA4.
Example: A Shopify store with $80,000 monthly revenue and $20 CAC explores a retainer. A structured retainer focusing on improved attribution, CRO and creative testing may aim to reduce CAC to $16-18 and increase revenue to $95,000-$110,000 over 6-9 months. These figures are illustrative estimates, not guarantees; outcomes depend on spend, margins, and test velocity.
Score proposals on a 5-point scale in three domains: Measurement (GA4 & server-side), Experimentation (CRO cadence and sample sizes), and Execution (developer resources and automation). A high-performing retainer will present a Plan with timelines and measurable milestones. For process examples and company background, review About Prebo Digital here.
If you want to explore how a structured retainer could map to your store or SaaS product, Prebo Digital outlines service offerings and long-term engagement models on the services page here and provides contact options here. Explore the framework and use the interview checklist above when evaluating proposals.
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