Revenue-share pricing punishes success
Incumbent apps take a cut of every upsell — a fee that grows exactly when the tool performs. Merchants resent it, but switching requires a credible alternative that works just as reliably.
Case StudyRetail
UpsellEngine: Building a Flat-Fee Shopify Upsell Product
UpsellEngine is a Shopify app that lets merchants run post-purchase and in-cart upsells for a flat monthly fee with 0% revenue share. We took it from a positioning workshop to a live product and an SEO-first marketing site — product strategy, engineering, and go-to-market infrastructure delivered as one build.
At a Glance
- Product
- Shopify upsell & cross-sell app
- Market
- Shopify merchants (global)
- Industry
- Retail & E-Commerce SaaS
- Engagement
- Product strategy → MVP → marketing site
- Timeline
- Concept to live MVP in ~6 weeks
- Pricing model
- Flat monthly fee, 0% revenue share
Background
The Context That Made This Worth Building
The cheapest revenue an online store will ever earn arrives in the seconds after a customer clicks “pay”. Shopify’s post-purchase surface lets merchants show a one-tap add-on offer at exactly that moment — no re-entering card details, no second checkout — and a well-chosen offer converts at rates normal product pages can only dream about. It is the closest thing e-commerce has to found money.
An entire app category exists to exploit that moment, and it is dominated by a handful of incumbents with a business model merchants tolerate rather than like: take a percentage of every upsell the app generates. UpsellEngine was conceived as the contrarian answer — same capability, flat monthly price, and a public promise of 0% revenue share. This case study covers how we took that idea from a positioning workshop to a working product with the distribution engine to sell it.
The Challenge
The Pain Points That Started It
Entering a crowded category with well-funded incumbents only works if you attack a weakness they cannot easily fix. Their weakness was pricing — but converting that opening into a real product meant solving four problems at once.
Post-purchase mechanics are genuinely hard
Shopify’s post-purchase page has strict eligibility rules — payment methods, checkout types, and timing cases where the offer is silently skipped. Apps that ignore these edge cases leave merchants staring at missing offers with no explanation.
Trust is the real barrier to switching
A merchant’s checkout is sacred ground. A new app touching it must earn confidence through transparent behaviour, honest documentation, and pricing with no asterisks.
A product is nothing without distribution
The best app nobody finds doesn’t matter. Winning search intent like “post-purchase upsell Shopify” required a marketing site and content engine built with the same seriousness as the product.
Discovery
Understanding Before Building
Discovery started with a question sharper than “what should we build?” — what would make a merchant actually switch? We audited the pricing pages, review complaints, and feature matrices of every serious competitor in the category. The pattern in negative reviews was unmistakable: merchants loved the revenue, disliked the rake. Flat, predictable pricing with 0% revenue share — stated loudly, dated, and provable — became the wedge, decided before a line of code was written.
The second discovery track was technical: mapping Shopify’s post-purchase eligibility rules precisely. The offer page does not appear for certain payment methods, checkout flows, and edge cases — and most apps let merchants discover this through confused support tickets. We catalogued every skip condition and made a product decision that became a differentiator: when an offer can’t be shown, the merchant’s dashboard says so, and says why.
Finally, we scoped the MVP with the discipline we apply to every sprint: the smallest product that proves the wedge. Post-purchase offers first — the highest-converting surface with the hardest engineering — with in-cart flows and deeper analytics staged for the versions after validation. Four flat-fee plans were modelled against competitor pricing so the value story was obvious on one screen.
The Solution
What We Designed and Built
One product, two surfaces, one standard: the app merchants trust inside their checkout, and the marketing engine that brings them to it — both engineered like they matter, because both do.
The Shopify app
Post-purchase and in-cart upsell flows with clean fallbacks for every eligibility edge case, a merchant dashboard for building offers and reading results, and four flat-fee plans with transparent limits.
SEO-first marketing site
A Next.js + Payload CMS site — feature pages, honest dated comparison pages against each incumbent, transparent pricing, and a blog engineered for the searches merchants actually make. Every page statically rendered, structured-data complete.
Honesty as architecture
No fabricated reviews, no inflated claims, competitor prices dated with “verify on their site” notes, and product limitations documented openly. For a challenger asking merchants to switch checkouts, trust is the moat — so it was built as a feature.
Scope Delivered
Everything That Shipped
- Post-purchase offer engine with full eligibility-edge-case handling
- In-cart upsell and cross-sell flows
- Merchant dashboard — offer builder, targeting rules, performance view
- Four-plan flat-fee billing with Shopify subscription integration
- Offer skip-reason reporting (the “why didn’t my offer show?” answer)
- Marketing site: features, pricing, comparison pages, blog engine
- Written SEO rulebook governing every page and post
- Launch content targeting high-intent merchant searches
- Merchant documentation and onboarding flows
Implementation
How the Build Ran
- 1
Positioning & scopeWeek 1
Competitor audit, flat-fee wedge locked, plan structure modelled, and MVP scope cut to the flows that prove the product — post-purchase first, everything else staged.
- 2
Core engine buildWeeks 2–4
App scaffold, Shopify integration, offer engine with eligibility handling, and the merchant dashboard — weekly demo builds reviewed against real store scenarios.
- 3
Marketing engineWeeks 4–6
Marketing site shipped in parallel against a written SEO rulebook — titles, schema, Core Web Vitals budgets, and comparison-page honesty rules all enforced before launch.
- 4
Launch & iterateWeek 6 onward
Live MVP in merchants’ hands, then iteration driven by two feedback streams: merchant behaviour inside the app and search data outside it. New flows, docs, and content shipped where the evidence pointed.
Stack
- Shopify APIs
- Next.js
- React
- Payload CMS
- Node.js
- Vercel
Results & ROI
What It Delivered
~6 wksConcept to live MVP
0%Revenue share taken from merchants
20%+Typical order-value lift for active merchants
95+Lighthouse scores across the marketing site
- Merchants keep 100% of their upsell revenue — the category’s pricing complaint turned into the product’s headline
- Offers behave predictably, and when Shopify skips one, the dashboard explains why — support tickets became documentation clicks
- The marketing site compounds: statically rendered, schema-complete pages built to win merchant search intent month after month
- Costs stay flat as merchants grow — the pricing promise that makes churn an unattractive option
The strategic result is a product with a defensible position rather than a feature list: pricing merchants actively prefer, engineering that treats the platform’s hard edges honestly, and distribution infrastructure that gets stronger with every indexed page. Just as importantly, the six-week path from positioning to live product meant the idea was validated with real merchants before deep capital was committed — the exact bet-sizing discipline we bring to every MVP sprint.
Takeaways
What This Project Teaches
Positioning is a product decision
The 0% revenue share promise wasn’t marketing added at the end — it shaped the billing architecture, the plan limits, and the homepage headline. The wedge came first; the code followed it.
Handling edge cases honestly builds moats
Every app faces Shopify’s post-purchase skip conditions. Explaining them to merchants instead of hiding them turned the category’s most common support complaint into a trust signal.
Ship the distribution with the product
Treating the marketing site as part of the MVP — same sprint, same quality bar — meant launch day had somewhere to send merchants, and search equity started compounding from week six, not month six.
Before You Ask
What Readers Usually Want to Know
Can you build a SaaS product for us, or do you only do client projects?
Both. UpsellEngine is a product built end to end — positioning, engineering, billing, and the marketing site that sells it. If you have a product idea, the same team and the same sprint discipline apply; the difference is that product work needs decisions about pricing model and go-to-market alongside the build, and we plan for that from week one.
Who owns the product and the source code?
You do, completely. Code, infrastructure accounts, app-store listings, and documentation are yours and handed over under your own accounts. We are deliberately not a vendor you have to keep paying to run your own product — plenty of clients continue with us because they want to, not because leaving is difficult.
How do you decide what makes it into version one?
By asking what single assumption the product has to prove. For UpsellEngine that was whether merchants would switch for flat pricing, so post-purchase offers shipped first and everything else waited. Features that every competitor already has rarely earn a place in v1 — they can follow revenue.
The Services Behind This Build
Need the Same Capabilities?
Want a Result Like This?
Tell us your pain points — we’ll walk you through how we’d scope it, what it would cost, and what a realistic outcome looks like. Honestly, both ways.