Another type of electronic mailing list is a discussion list, in which any subscriber may post. On a discussion list, a subscriber uses the mailing list to send messages to all the other subscribers, who may answer in similar fashion. Thus, actual discussion and information exchanges can happen. Mailing lists of this type are usually topic-oriented (for example, politics, scientific discussion, health problems, joke contests), and the topic may range from extremely narrow to "whatever you think could interest us". In this they are similar to Usenet newsgroups, another form of discussion group that may have an aversion to off-topic messages.
From a business perspective, emails are widely used as a cost-effective as well as efficient way of acquiring new customers, boosting sales, building up your brand awareness and fostering a sense of trust among your customers. Email marketing has also shown a better ROI compared to other marketing channels. According to a survey conducted by Direct Marketing Association and Demand Metric, email had an ROI of nearly 122%, whereas other channels such as social media had just 28%.