In short, there are no ads sent by Viber and there never will be.
Because Viber is completely free both as an application and service, many people wonder if Viber will add advertisements to its current services in the future. Well, here is the official statement on this issue:
1. Viber software will always be free.
2. Viber will never display any ads.
3. Viber to Viber calls will always be free.
4. Viber to Viber text messages will always be free.
If you are wondering if there is a possibility to advertise through Viber (through messages, calls, banners), the answer is no. Viber is not meant to be used for anything other than personal use and there are no plans to develop advertising plans. Any form of advertising will be considered spam.
Unfortunately, though, some people will use Viber to send spam to people, so if you do get a request to add a user that you don’t know or some message that seems shady or untrustworthy, let Viber know! You can ask for support on this page–just be sure to mention that you are getting spam and try to provide as much detail as possible.