Tribalism

You could frame sign-up as an 'adventure' with developer-style Y/N inputs, using tribalism so a niche audience feels the product speaks their language.

Example from

GitHub

Try letting groups create their own custom emojis, so shared in-jokes grow inside the space and members feel a stronger sense of tribalism with each other.

Example from

Slack

You could turn a dead-end 404 page into an interactive quiz for a niche audience, e.g., designers, so the in-group reference makes them feel part of the tribe.

Example from

Mobbin

On shared or family plans, you could show everyone's avatars together in a banner, reinforcing the small tribe that each member feels part of.

Example from

Duolingo

When someone joins a group, you could show how many people like them are already there, signalling they've found their tribe before they commit.

Example from

Discord