Part Two: The product · Everyday use
More people in the product is good for the company. Sharing pushed on someone who only wants to get their own work done is an intrusion.
Someone opens a note-taking app to write a shopping list. A banner says "Invite your team to collaborate!" The largest button on the screen is Share. A week later an email arrives: "Notes are better together." She wanted a list.
Every customer who invites someone brings in a new customer for nothing, and a product that spreads through use grows more cheaply than one that has to advertise. So the people responsible for growth want an invitation on every screen.
For some products, other people are the point. A shared document with one reader is just a file. Team chat with one member is a diary. The mistake is treating every product as if it were one of those.
The cost is paid in trust. A person who is unsure who can see their work writes less of it down. They wonder whether the app has just emailed their contacts. In software a company has bought, they wonder whether the draft they are thinking aloud in is already visible to their manager.
There is a right moment for sharing, and the work provides it. She wants her husband to see the list. A music teacher wants a pupil's parents to see this week's practice notes. A report needs someone's approval. At that moment sharing should be easy and exact about what the other person will see. It should not make the other person open an account just to look.
Therefore:
Let a person do their own work alone and in private by default. Offer sharing at the moment the work needs someone else, say exactly what that person will see, and let them look without joining.
In practice. Count every prompt to invite or share that a new customer working alone sees in their first week. Remove each one that is not attached to a moment when the work needs another person.
Goes with. The invited person's arrival is SET UP BY ONE, USED BY MANY (38). Saying what they will see is SAY WHAT HAPPENS NEXT (81), and privacy by default is part of being TRUSTED WITH THEIR DATA (58).