When the business is small, the easiest and free way is to make a mailing using standard WhatsApp tools. To do this, click on the three dots at the top of the screen and select "New mailing". Then all that remains is to mark the necessary contacts and write the text. The downside is that you will have to personally respond to each message, but with a small client base, this method will be optimal.
For the self-employed and entrepreneurs in the service sector (beauty salon, legal advice, handmade), the free WhatsApp Business App is suitable. It is compatible with both Android and iOS, and can also be jiangsu mobile number database installed on a computer. The interface is similar to the standard WhatsApp application, but with additional features. For example, it is possible to create a company profile, where contacts and a website are indicated, track message statistics, as well as sort and quickly respond to messages. It is worth considering that the application allows you to send mailings only to those contacts that are recorded in the address book, and at the same time have added you to theirs.
There is also a more modern solution for medium and large businesses that have a large contact base and, accordingly, an impressive flow of messages - this is a paid application WhatsApp Business API. It integrates with the site, CRM system and contact center. What is important is that it allows sending to addresses not added to the contact book. And it also has additional options, such as support for chat bots and the creation of multi-level campaigns.