{
  "subscriberId": "subscriber_123",
  "email": "jane@example.com",
  "firstName": "Jane",
  "lastName": "Doe",
  "phone": "+15555550101",
  "avatar": "https://cdn.acme.com/avatars/jane.png",
  "locale": "en-US",
  "timezone": "America/Los_Angeles",
  "data": {
    "plan": "pro",
    "organizationId": "org_acme"
  }
}