轻松一站管理来自不同社交平台的讯息！利用独家营销自动化功能，改善顾客体验！ WhatsApp uses a "keep and ahead" mechanism for exchanging messages among two customers. Every time a person sends a information, it is stored with a WhatsApp server, which attempts to ahead it for the addressee, and continuously requests acknowledgement of receipt. 知乎，让每一次点击都充满意义 —— 欢迎来到知乎，... https://apps-whatsapp.com/whatsapp-web