Aside from all advertising through social networks and aside from blogging, the oldest form of digital social networks is undoubtedly email. There is no marketing expert who hasn't started their communication or advertising with email. To cope with email advertising you have to be an expert in communication who ideally solves problems, gathers new customers and develops a web of trust. Email is an original social media in which the communication is two-sided: between you and your customers. The rule is, if you haven't managed email marketing, don't even bother to run the social networks because you are missing the right starting point.