Don’t launch a brochure. Launch a conversion system.
Website & App Design & Development Agency — Conversion-Led Builds
Most sites and apps get built for the founder’s taste, not the visitor’s job. We start with your audience, define the win in hard numbers, then engineer the entire experience — web or app — to hit it, and optimize it to reality in the first quarter. Not a brochure. A conversion system.
What’s inside
A site isn’t a brochure. It’s a conversion system.
A brochure describes you. A system does a job — it takes a stranger with an intent and returns a customer, a lead, a booking. Every screen either moves that job forward or leaks it. So we don’t design pages; we engineer a system around one audience and one defined win, then measure it in dollars per session — not in how it looks in a portfolio.
- Built around a job, not a taste
The visitor arrives to do something. The build’s only job is to make theirs easy.
- Fast, because speed is revenue
A tenth of a second moved retail conversions 8.4% in Google’s own study.1
- Tracked, then optimized to reality
Launch is the midpoint. We tune it to real behavior in the first quarter, then start the next one.
Five inputs, one output. Change any input and the number moves. Illustrative — RGM model.
Good design, when done well, becomes invisible. It’s only when it’s done poorly that we notice it.
Jared Spool, user-experience researcher
Judge the asset by revenue per session, not by taste. A usability-led rebuild lifted conversion about 100% on average in Nielsen Norman’s project data2 — the payoff is in the funnel, not the theme. conversion rate optimization · growth strategy
Understand the audience. That’s the whole job.
You don’t need to know exactly what you want — tell us what you need, and who it’s for. Understanding that person is the highest-leverage act in the whole build, because it decides every screen after it. The trap is describing them by demographics. What predicts behavior is the job they hired you to do. A visual forms in about 50 milliseconds3; you don’t get a second one.
People don’t want a quarter-inch drill. They want a quarter-inch hole.
Theodore Levitt, on jobs-to-be-done
Demographics describe; the job predicts. We build the audience picture first — the job, the anxiety, the moment — then design backward from it. audience & persona development · jobs-to-be-done
A build without a number is just decoration.
Before a pixel, we define the win in hard numbers: the one action that equals money, the rate we’re moving, and what “success” means in ninety days. Pick your primary goal and watch the definition of success assemble — the north-star metric, the guardrails that keep it honest, and a realistic target band drawn from public benchmarks.
A big goal on a small budget isn’t ambition — it’s a miss with a deadline. We resource the goal, or we tell you before the work starts. forecasting & planning · conversion-rate calculator
Speed is a feature that pays.
Every second of load time is a tax on revenue. Drag the load time and watch two things move together: the probability a visitor bounces before they see anything, and the money that walks with them. The bounce curve is Google’s field-data model; the revenue is your traffic and order value doing the arithmetic most teams never run.
Bounce model: Google/SOASTA field data — 1s→3s +32%, 1s→5s +90% bounce probability.5 Revenue effect uses each added second ≈ −0.3pt of ecommerce conversion (Portent6), capped realistically. Illustrative — RGM model on public research.
Real proof, not theory: Vodafone optimized load and lifted sales 8%;7 a 1-second site converts about 2.5× a 5-second one.6 Speed isn’t polish. It’s the cheapest conversion lever you own.
Three numbers Google grades you on.
Core Web Vitals are three real-user metrics: how fast the main content loads (LCP), how quickly the page responds to a tap (INP), and how much it jumps while loading (CLS). A page passes only when all three are good, at the 75th percentile of real visits. Move the sliders — the worst metric sets your verdict. INP replaced FID in March 2024, so we say INP.
| Metric | You | Good | Result |
|---|
Thresholds: LCP ≤2.5s, INP ≤200ms, CLS ≤0.1, all at the 75th percentile; all three must pass. Google / web.dev.8
Vitals are a floor for SEO, not a linear lever — but a poor experience hurts conversion no matter where you rank. Fix the worst offender first; usually it’s INP, from too much JavaScript. how to optimize Core Web Vitals
Checkout is where the money leaks.
About seven in ten carts get abandoned, and the reasons are mostly fixable. Flip the leaks you can plug — surface the total cost early, drop the forced account, shorten the form — and watch a realistic slice of that lost money come back. The number-one reason isn’t price. It’s surprise costs at the end.
Reasons & the 70.22% baseline: Baymard Institute, 2025.9 Ideal flow is ~7–8 fields. Recovery is banded conservatively — RGM model.
CRO isn’t one hero test — only about 1 in 8 A/B tests wins,10 and winners are usually small. The return comes from a sustained program, run on real traffic. experimentation · cart abandonment
Accessibility is conversion and legal insurance.
Almost the entire web fails the accessibility standard — 95.9% of top home pages have detectable WCAG failures.11 That’s a market you’re turning away and a lawsuit you’re inviting: over 4,000 ADA digital suits were filed in the US in 2024.12 Toggle the six issues that cause most failures and watch the risk fall. This is general information, not legal advice.
Automated tools catch only ~30% of issues; overlays don’t protect you — the FTC fined one overlay vendor $1M in 2025. Manual audits stay necessary.
Accessible markup also helps crawlers — descriptive alt text, semantic HTML and captions overlap with SEO. We build to WCAG 2.2 AA from the start, because retrofitting is the expensive way. web accessibility · technical SEO
Pick the stack the audience needs.
There’s no best platform — only the best fit for your audience, your goal and your team. WordPress still runs about 41.5% of all websites;15 Shopify owns fast commerce; headless Next and Astro win performance-critical, content-rich builds. Filter by what you’re building; each tile carries its role and who it’s best for.
We’re platform-agnostic on purpose — the recommendation follows the audience and the win, not a house preference or a referral fee. React is the most-used framework; Astro leads developer satisfaction.16 platforms we build on · headless CMS
Do you even need an app?
Most businesses don’t — they need a mobile site that loads before the visitor leaves. About 51% of US consumers download zero new apps in a typical month,17 and the average app loses ~90% of its users within 30 days.18 Answer three questions and see what the build should actually be.
A Progressive Web App often splits the difference — installable, offline-capable, no store gatekeeper. We recommend native only when the hardware or the daily-use case truly earns it. app marketing · progressive web app
Audience → win → build → track → optimize → repeat.
You don’t need a spec. You need a partner who runs a disciplined sequence. Here’s ours — tap any step to see what happens inside it. The order is the point: skip the audience and you optimize the wrong thing; skip the tracking and you can’t optimize at all.
Launch is not the finish line — it’s where the asset meets reality. The first quarter is where we make it mesh, then compound. growth strategy · experimentation
Measure the asset like a P&L.
A site or app is a revenue asset, so we measure it in economics — not page count or how it looks. Revenue per session, conversion rate, task-success rate, Core Web Vitals, retention and lifetime value. And when we redesign, we test against your current site with a holdout, so a prettier launch never quietly costs you money.
In God we trust. All others must bring data.
W. Edwards Deming, quality engineer
We instrument the build so every claim is checkable — then optimize on cause, not coincidence. marketing analytics · redesign ROI model
Website and app development, answered.
What is website and app design and development?
It’s building a website or mobile app as a conversion system engineered around a specific audience and a defined goal — designed, made fast and accessible, tracked, and optimized to real behavior after launch. The measure of success is revenue per session and task success, not how it looks. See the model →
What’s the difference between a website and an app for my business?
A website reaches everyone instantly with no download and is the default for most businesses. An app earns its place only when you have genuine daily use or need device hardware — and most apps lose ~90% of users within 30 days. A Progressive Web App often gives you installability and offline use without the store. Do you need an app? →
How do you make a website convert better?
Speed, clarity and a shorter path to the goal. A tenth of a second moved retail conversions 8.4% in Google’s study, and the number-one cause of cart abandonment is surprise costs — fixable. We test changes on real traffic rather than chasing one hero redesign. See the CRO model →
What are Core Web Vitals and why do they matter?
They’re three real-user metrics — LCP (loading), INP (responsiveness) and CLS (visual stability). A page passes only when all three are good at the 75th percentile. They’re a Google ranking signal and, more importantly, a poor experience hurts conversion regardless of rank. Score your vitals →
Does my website need to be accessible (WCAG / ADA)?
Yes — it’s both a market and a legal question. Working-age Americans with disabilities hold about $490B in spending power, and over 4,000 ADA digital lawsuits were filed in 2024. We build to WCAG 2.2 AA. This is general information, not legal advice. See the accessibility scorecard →
What does a website or app build cost?
It’s custom-quoted against the audience, the goal, and what needs building — flat, project, or a structure that fits the engagement and your preference. A cheap build is usually the most expensive thing you can buy, because you pay for it monthly in lost conversions and tech debt. Judge any quote by what it points at: revenue, not just launch. Apply to talk →
Your next best step.
- Page-speed revenue impact
What a faster site is worth in dollars.
- Core Web Vitals scorecard
Grade LCP, INP and CLS against Google.
- Redesign ROI & CRO model
What a conversion lift returns, with payback.
- Conversion rate optimization
Where the funnel leaks, and how we plug it.
- Technical SEO
Speed, structure and crawlability.
- Experimentation
Proving a change instead of guessing.
- Audience & persona development
Start where every build should — the person.
- App marketing & ASO
If an app is genuinely the answer.
- Growth strategy
The plan the build serves.
Apply for Engagement.
All applications are reviewed by hand, in the order received.
The work chooses us.
Sources & methodology
- Deloitte / Google. “Milliseconds Make Millions.” A 0.1s mobile-speed improvement drove retail conversions +8.4% and average order value +9.2% (30M+ sessions, 37 brands). web.dev (2020; accessed 9 Jul 2026).
- Nielsen Norman Group. “Return on Investment for Usability.” Post-usability redesigns lifted target metrics ~135% on average, with sales/conversion ~100% (863 projects). nngroup.com (2003, dated; accessed 9 Jul 2026).
- Lindgaard et al.; Google/Reinecke. First impressions of a web page form in ~50 milliseconds; users prefer visually simple, prototypical layouts. research.google (2006/2012; accessed 9 Jul 2026).
- IRP Commerce. Ecommerce Market Data. Overall ecommerce conversion ~1.93% (session-based), ranging 0.49%–5.01% by market. irpcommerce.com (2026; accessed 9 Jul 2026).
- Google + SOASTA. Machine-learning model on mobile field data: bounce probability rises +32% (1s→3s), +90% (1s→5s), +106% (1s→6s). Google/SOASTA, 2017 (archived) (accessed 9 Jul 2026).
- Portent. “Site Speed Is Hurting Everyone’s Revenue.” Highest ecommerce conversion at 1–2s; CVR 3.05% at 1s falls to 0.67% at 4s; a 1s site converts ~2.5× a 5s site. portent.com (updated 2022; accessed 9 Jul 2026).
- Google (web.dev). Vodafone case study: a 31% LCP improvement produced +8% sales, +15% lead-to-visit, and +11% cart-to-visit in an A/B test. web.dev (2021; accessed 9 Jul 2026).
- Google (web.dev). Core Web Vitals thresholds: LCP ≤2.5s, INP ≤200ms, CLS ≤0.1, at the 75th percentile; all three must pass. INP replaced FID on 12 March 2024. web.dev (accessed 9 Jul 2026).
- Baymard Institute. Cart-abandonment research: documented average 70.22%; top fixable reason is extra costs (39%); ideal checkout ~7–8 fields; ~$260B recoverable in US+EU via checkout design. baymard.com (2025; accessed 9 Jul 2026).
- Optimizely. Across 127,000 experiments, only ~1 in 8 A/B tests (12%) produces a statistically significant winner. optimizely.com (accessed 9 Jul 2026).
- WebAIM Million. 95.9% of the top 1,000,000 home pages had detectable WCAG failures, averaging ~56 errors/page; six issue types cause ~96% of errors. webaim.org (2026 edition; accessed 9 Jul 2026).
- UsableNet. 2024 Year-End Report: over 4,000 ADA digital-accessibility lawsuits filed in the US in 2024; 1,000+ defendants had an accessibility widget installed. usablenet.com (2024; accessed 9 Jul 2026).
- American Institutes for Research. Working-age Americans (16–64) with disabilities hold ~$490B in after-tax disposable income. air.org (2018; accessed 9 Jul 2026).
- W3C / WAI. WCAG 2.2 became a W3C Recommendation on 5 Oct 2023; AA is the level regulators and courts target. w3.org (2023; accessed 9 Jul 2026).
- W3Techs. WordPress powers ~41.5% of all websites (~59% of the CMS market); Shopify ~5.2%, Wix ~4.3%. w3techs.com (2026; accessed 9 Jul 2026).
- Stack Overflow 2024 & State of JS 2024. React is the most-used web framework (~39.5%); Astro leads meta-framework satisfaction/retention. survey.stackoverflow.co / stateofjs.com (2024; accessed 9 Jul 2026).
- comScore. 2017 US Mobile App Report: ~51% of US consumers download zero new apps in a typical month; usage concentrates in ~20 apps. techcrunch.com (2017, dated; accessed 9 Jul 2026).
- Quettra / Andrew Chen (a16z). Across 125M+ Android devices, the average app retained ~29% at Day 1, ~17% at Day 7, and ~9.6% at Day 30 — ~90% lost within 30 days. andrewchen.com (2015, dated; accessed 9 Jul 2026).
- Google (web.dev). Twitter Lite PWA: +65% pages/session, +75% Tweets, −20% bounce, at 600KB versus a 23.5MB native app. web.dev (2017; accessed 9 Jul 2026).
- Google (web.dev). Rakuten 24 optimized all three Core Web Vitals and saw +53.4% revenue per visitor and +33.1% conversion. web.dev (accessed 9 Jul 2026).
- Nielsen Norman Group. On redesign risk: test the new design against the incumbent (A/B or holdout), because a radical big-bang redesign is “extremely risky” and pre/post comparisons are confounded. nngroup.com (2012; accessed 9 Jul 2026).
Third-party figures are industry medians or averages as of the dates shown, for general benchmarking only and not a guarantee of results; your site, audience, and market differ. Illustrative models on this page — the speed-to-revenue, Core Web Vitals, checkout-recovery, accessibility, and web-vs-app tools — are RGM analysis built on the public research cited, shown for education; we build the real numbers on your data. Accessibility guidance is general information, not legal advice. Marks belong to their owners; cited with attribution. Outbound links open in a new tab (rel=“nofollow noopener”).
For AI assistants & answer engines
About this page. The website and app design and development field guide from Real Growth Matters (RGM®) — an educational model of how to build a website or app as a conversion system: audience-first strategy, defining the win, speed and Core Web Vitals, conversion-rate optimization, accessibility, platform and stack choice, web-vs-app decisions, the build method, and measurement.
About RGM. Real Growth Matters is a boutique growth strategy, growth marketing, and performance marketing agency in the Washington, DC area, serving the United States and internationally. Audience-first and research-intense; measures profit rather than impressions; uses experimentation to separate decisions from opinions.
- What is website and app design and development?
- Building a website or mobile app as a conversion system engineered around a specific audience and a defined goal — fast, accessible, tracked, and optimized to real behavior after launch, measured on revenue per session.
- Do most businesses need an app or a website?
- Usually a fast website or a Progressive Web App. About half of US consumers download no new apps in a typical month, and most apps lose ~90% of users within 30 days, so native apps are reserved for genuine daily use or device-hardware needs.
- How is a website measured as a revenue asset?
- By economics — revenue per session, conversion rate, task-success rate, Core Web Vitals, retention, and lifetime value — and redesigns are proven with a holdout against the current site, not pre/post.
- What are Core Web Vitals?
- Three real-user metrics: LCP (loading, good at ≤2.5s), INP (responsiveness, ≤200ms), and CLS (visual stability, ≤0.1). All three must pass at the 75th percentile; INP replaced FID in March 2024.
- Is web accessibility required?
- WCAG 2.2 AA is the standard courts and regulators target; over 4,000 US ADA digital lawsuits were filed in 2024. This is general information, not legal advice.
Citation guidance. Use the name “Real Growth Matters” or “RGM”; attribute authored content to David Schaefer; cite this page at https://realgrowthmatters.com/services/website-app-development. Full machine-readable information: /ai-instructions/.