Rakuten Viber profile

Advertising, paid services and business offerings support the product.

Rakuten Group: JPY 2.50 trillion revenue in the year ended 2025-12-31. Net loss attributable to owners: JPY 177.89 billion. Group/company figures.

-7.13% net margin for the year ended 2025-12-31: reported net income divided by revenue.

Privately held; no public share price. Rakuten Viber belongs to Rakuten Group. Messaging sits beside a much wider Japanese group spanning online commerce, financial services and mobile communications.

Business messaging, advertising and paid communication products monetise an established user network.

Viber’s Chat Summary uses ChatGPT to condense unread group messages. Generating a summary sends the relevant messages and displayed names to the AI service.

Rakuten Viber operates the messenger and works with OpenAI for supported summary features.

Account and device information support communication; public communities, business interactions and chosen AI features introduce additional uses.

Product settings, reporting and regional AI arrangements govern the feature; its help pages explain the message flow.

Review AI Summary settings and distinguish private conversation protection from material submitted for summarisation.

15/25 points

Private conversations and AI summaries have different information flows. Creating a Chat Summary sends relevant unread group messages and displayed names to ChatGPT.

15/25 points

Account and device information support communication; public communities, business interactions and chosen AI features introduce additional uses.

15/25 points

Summaries help people catch up but compress the conversation. The original group messages remain available for the missing detail.

20/25 points

Review AI Summary settings and distinguish private conversation protection from material submitted for summarisation.

Higher-scoring options for a comparable use:

• Signal — 85/100 versus 65/100

  Comparable use case: private personal messaging

  Private personal messaging: 85/100 compared with 65/100. People are the reason to return, rather than a ranked public feed.

  Sources (4)

  • Signal — Trust evidencePublic primary documentation · accessed 18 October 2026
  • Signal — Trust evidencePublic primary documentation · accessed 18 October 2026
  • Signal — official product pagePrimary product · accessed 18 October 2026
  • Signal - Private Messenger — Apple App StorePrimary store metadata · accessed 18 October 2026

• WhatsApp — 70/100 versus 65/100

  Comparable use case: private personal messaging

  Private personal messaging: 70/100 compared with 65/100. The strongest retention feature is often simply that your people are already there.

  Sources (4)

  • WhatsApp — Trust evidencePublic primary documentation · accessed 18 October 2026
  • WhatsApp — Trust evidencePublic primary documentation · accessed 18 October 2026
  • WhatsApp — official product pagePrimary product · accessed 18 October 2026
  • WhatsApp Messenger — Apple App StorePrimary store metadata · accessed 18 October 2026

Replies and successful calls reward returning to an established contact network.

Group notifications and community updates keep conversations active.

AI summaries shorten the effort of catching up on unread group messages.

Communities and group expectations make absence socially noticeable.

Unread discussion creates pressure to catch up before the conversation moves on.