How these notes work, and who they are for
Short answer
These notes answer the questions people ask before they hire a designer and developer: what it costs, whether it pays, what can go wrong. Each one gives the answer first and links every number to its source.
Contents 6 sections
I make websites, brands and products for companies that need them to earn money. These notes are where I write down what I learn doing it: what things cost, why, and what I would do with your budget.
They are written for a buyer. If you run a company or its marketing and you are about to spend five figures on design and development, you are who I have in mind. If you are a designer who came for the pen plotter, welcome too. The pen is in the margin.
What is a note for?
A note answers one question that someone asks before they hire me. How much is a website. Will it pay for itself. Can I change platform and keep my search traffic. Those are the questions a first call starts with, so I may as well answer them once, properly, where you can read the answer without booking anything.
Every note is built the same way.
- The question is the title. No wordplay. If you searched for it, you should recognise it.
- The short answer comes first. It sits under the title, in one or two sentences. If that is all you read, you still leave with something.
- Then the evidence. Numbers, each with a link to where it comes from. My own experience, marked as mine.
- Then something you can use. A checklist, a sum, a tool you can drag.
- One sentence about what I sell. At the end, once, after the note has done its job.
If a number has no source, it does not go in.
Where do the numbers come from?
From someone I can name, at an address you can open. Here is one.
The weight of the median home page when it loads on a phone.
Source: HTTP Archive Web Almanac, 2025
That block is the only way a statistic gets into a note. It asks for a link and a year. Leave either out and the site refuses to build,11Only on the live site. On my machine and on preview links it shows a red tag where the source is missing, so one mistake does not take everything down. which makes it a stricter editor than any I have worked with.
Smaller facts get a footnote instead. Google’s own speed test calls 1.6 megabits a second “Slow 4G”.22Lighthouse’s throttling guide gives “Slow 4G” as 1.6 Mbps down with 150 ms of latency, “roughly the bottom 25% of 4G connections”. Lighthouse on GitHub, checked 11 November 2026. On a wide screen that footnote sits in the margin, next to the sentence it belongs to. On a phone it waits at the bottom with a link back.
Put the two numbers together and the median page is a wait. At 1.6 megabits a second, 2.56 megabytes takes 12.8 seconds to arrive. That is arithmetic, not a study, so you can check it by dragging.
- Fig.
- Interactive
- Page weight, time and money
- Use it
- Drag the weight. Type your own numbers.
On this line every extra 100 KB adds 0.50 s. That is before the browser has parsed or painted anything.
What one tenth of a second is worth, at your numbers
Example numbers. Replace them with yours. The study measured one step of 0.1 s on retail and travel sites. It does not say ten steps are worth ten times as much, and your site was not in it. Read the result as the size of the prize, not a forecast.
Benchmarks used
- “Slow 4G” is 1.6 Mbps down with 150 ms of latency: roughly the bottom 25% of 4G connections. Lighthouse throttling guide, checked Nov 2026
- The median home page weighs 2.56 MB on mobile and 2.86 MB on desktop. HTTP Archive Web Almanac, Page Weight, July 2025 data
- A good Largest Contentful Paint is 2.5 seconds or less, at the 75th percentile of page loads. web.dev, Largest Contentful Paint, updated Sept 2025
- A 0.1 s faster mobile site raised conversion rates by 8.4% for retail sites and 10.1% for travel sites (37 brand sites, 30 days). 55 and Deloitte for Google, Milliseconds Make Millions, data from late 2019
Numbers that belong together sit side by side.
More retail conversions from a mobile site that is 0.1 s faster.
Source: 55 and Deloitte for Google, 2019
More travel conversions. Same study, same 0.1 s.
Source: 55 and Deloitte for Google, 2019
When I quote someone, the quote is short and the link is right under it.
…sites should strive to have Largest Contentful Paint of 2.5 seconds or less.
What can a note show?
More than paragraphs. These are the parts I have to work with.
A claim, before and after
A claim
Fast sites convert better.
The same claim, with its papers
A mobile site that was 0.1 s faster converted 8.4% more retail visitors, in a 30-day study of 37 brands at the end of 2019.
A table
| Number | What it measures | Who says so | Year |
|---|---|---|---|
| 2.56 MB | The median home page on a phone | HTTP Archive | 2025 |
| 1.6 Mbps | “Slow 4G” in Google’s Lighthouse | Lighthouse guide | checked 2026 |
| 2.5 s | A good largest paint | web.dev | 2025 |
| +8.4% | Retail conversions per 0.1 s | 55 and Deloitte | 2019 |
On a phone the table scrolls inside its own box. The page stays put.
Prices that cannot go stale
Drawings
Every figure is drawn by the same plotter as the rest of the site, the first time it scrolls into view. There are four to pick from.
- Fig.
- Fig.
- Source
- HTTP Archive Web Almanac
- Fig.
- Fig.
Any other figure
- Fig.
Code, when a note needs it
Most will not. When one does, the block says which file it is and has a copy button.
// drafts show in development and on preview links, never in production
export const SHOW_DRAFTS = process.env.VERCEL_ENV !== "production";A checklist
Before a note goes live, it has to pass this.
- The title is a question a buyer asks.
- The answer is in the first two sentences.
- Every number has a source and a year.
- Anything only I can confirm, I have confirmed.
- It has a date, and a new date when it changes.
- It ends with one sentence about what I sell, not five.
What does a late launch cost?
One more thing you can touch. A launch that slips has a price, and you can work it out without me.
- Fig.
- Interactive
- What a week of delay costs
- Use it
- Type your own numbers. Drag the weeks.
Where the numbers come from
Example numbers. Replace them with yours. Every figure above is yours: (monthly revenue + people × monthly cost) × 12 ÷ 52, times the weeks. No benchmark is applied, because I could not confirm one at its source. It also leaves out what a late launch does to a funding round or a sales quarter, which only you can price.
And the big one: when the work has paid for itself. The price is one of mine; everything else is yours.
- Fig.
- Interactive
- When the work pays for itself
- Use it
- Pick a price. Type what one customer leaves you.
Example numbers. Replace them with yours. On your numbers it pays for itself inside a year. A sum, not a forecast: it says when the work would have paid for itself if those customers come. Website is my starting price, $16,000; yours comes in writing after the call.
Where the numbers come from
Every figure is yours apart from the price, which is read from my pricing page. Customers to win = price ÷ what one customer leaves you. Months = that ÷ extra customers a month. No benchmark is applied.
How does a note get published?
Slowly. Every note starts as a draft. A draft shows on my machine and on preview links, with a tag that says so. On the live site it does not exist: not in the list, not in the feed, not at its own address.
While a note is a draft, anything only I can confirm carries a comment in the file. The comment never reaches the page. A separate page lists every one of them, so I can see what I still owe a note before I publish it.
Three weeks is typical for a move like this.
{/* CHECK: is three weeks right? Use the figure from a real project. */}How do I follow along?
There is an RSS feed. Every note has a “Copy as markdown” button under its title, and the same text lives at the note’s address with /md on the end. That is for people who keep notes, and for the AI tools that read on their behalf.
There is no newsletter to sign up for. I would rather you read one note than get an email every week.
That is the whole system. The next notes are about your money, not my blog.
Notes and sources
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Only on the live site. On my machine and on preview links it shows a red tag where the source is missing, so one mistake does not take everything down. ↩︎
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Lighthouse’s throttling guide gives “Slow 4G” as 1.6 Mbps down with 150 ms of latency, “roughly the bottom 25% of 4G connections”. Lighthouse on GitHub, checked 11 November 2026. ↩︎
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Milliseconds Make Millions, commissioned by Google and run by 55 and Deloitte: 37 brand sites, over 30 million sessions, 30 days at the end of 2019. Summary on web.dev. ↩︎
Written by Dion Zeneli. AI helped with research and editing. Sources are linked where they are used. Read this note as markdown.