The personal communication about a product or service through target clients' networks is referred to as what?

The scenario described involves the dissemination of information about a product or service through personal networks, which is best identified as word-of-mouth marketing. This type of marketing relies on individuals sharing their experiences and opinions directly with others, creating a grassroots level of promotion that can be highly effective due to its authentic and personal nature.

Digital marketing refers to online strategies for promoting products or services, typically involving social media, email, and other digital channels rather than personal networks. Paid advertisements involve using financial resources to promote content through various media, including online platforms, which again differs from the organic sharing characteristic of word-of-mouth. Viral marketing is a strategy aimed at creating interest and buzz that spreads quickly across the internet; while it shares similarities with word-of-mouth, it is usually more deliberate and campaigns are designed to go viral in a short period of time, which isn't strictly about personal networks.

In summary, the correct term for the personal communication about a product or service shared through target clients' networks is recognized specifically as word-of-mouth marketing, showcasing the influence of interpersonal trust and communication in effective marketing practices.