Pay-per-use reader

The Satoshi Vision sells articles one at a time. An article costs about 1p (20 sats). There is no subscription, no account and no email address. A reader pays from her own wallet. Once she reads often enough to want it, she gives The Satoshi Vision a small daily allowance, so articles open without a prompt.

This section walks through the design screen by screen, from the first visit to taking the permission away.

Who it is for

The reader is Anna Keller, reading on her phone with Bitcoin SV Wallet. She reads a few articles from The Satoshi Vision most days, follows links to it from elsewhere, and would never subscribe to it.

Anna is closest to Ilse, privacy-minded: somebody who wants to buy a newspaper without attaching a phone number to it, and who reads what she agrees to. If Ilse would stop at a screen, the screen is wrong. The team building The Satoshi Vision is closer to Emma, who fears losing readers at the first prompt.

On a phone, The Satoshi Vision opens inside Bitcoin SV Wallet's built-in browser, which passes its requests to the wallet. That is how a connected app works on mobile, and it is why the wallet's prompts appear as sheets over the article.

What it does

• Shows a free front page with a price on every paid article.
• Asks to connect only when Anna opens her first paid article.
• Takes one payment per article, from Anna's wallet to The Satoshi Vision.
• Offers an allowance after the first payment, never before it.
• Shows what the allowance has spent, and how to stop it, at the top of every article it paid for.
• Keeps a receipt page, pays refunds as new payments, and announces price changes to people with an allowance.

The business model is pay per use with a prepaid allowance, and the allowance lives in Anna's wallet. The Satoshi Vision never holds a balance for her.

The flows

1. First visit and connecting. The free front page, the price on each article, connecting at the first paid article, the first payment, and the offer of an allowance once that payment has gone through.
2. Reading and the meter. Paying inside the allowance with no prompt, the running total and stop control at the top of the article, the allowance running out, and a payment that fails.
3. Receipts, refunds and leaving. What Bitcoin SV Wallet's activity shows, the receipt page in the app, a refund, a price change, and revoking The Satoshi Vision from the wallet.

The patterns it applies

• Connecting a wallet, for asking for the minimum at the moment it is needed.
• Signing in, for recognising Anna by a key her wallet makes for this site alone.
• Permissions and allowances, for the wording, size and expiry of the allowance, and for revoking it.
• Charging per use, for the running total, the stop control, grouping and failures.
• Amounts and units, for local currency first on prices and satoshis first on the allowance.
• Errors and failed payments, for every message that follows a payment attempt.
• Pricing, for showing the price before the tap, rounding, price changes and refunds.
• Activity, for what Bitcoin SV Wallet shows afterwards.

What it deliberately leaves out

• A subscription. The allowance does its job, with a ceiling Anna chose and an end date.
• An account. No email, no password, no profile. Receipts by email are a separate, optional step.
• A balance held by The Satoshi Vision. Credits bought in advance are a custody problem the allowance avoids. See Custody as a product decision.
• Advertising. A paid article carries no ads, and says so.
• Metering by time. Anna buys an article, not minutes of reading. A per-second meter would charge in pieces for what she thinks of as one thing.
• Anna's identity. The Satoshi Vision never asks for her root identity key, a Pass or her transaction history.

On other platforms

The reader is a website, and on a phone it opens inside the wallet's browser, which is what lets every 20-sat article be paid without leaving the page. As an installed iPhone app it would change in two ways:

• The allowance would come from an app whose name the wallet cannot check, so it should start smaller and grow only after the reader has come back a few times.
• Each payment that goes past the allowance would mean a trip to the wallet and back, so the reader has to keep the article and the scroll position exactly where they were.

A shared article opened in Safari or Chrome is the case to design first: the article page loads, and paying asks the person to open it in their wallet's browser. See Websites on a phone.

How to use this

Related

• Connected web app: the same wallet signing in to a ticket shop
• Agent with a budget: an assistant buying articles from The Satoshi Vision for somebody else
• Daily spending wallet: the wallet side of these screens
• Business models