Email marketing is directly sending a commercial message, typically to a group of people, using email. In its broadest sense, every email sent to a potential or current customer could be considered email marketing. It usually involves using email to send ads, request business, or solicit sales or donations, and is meant to build loyalty, trust, or brand awareness. Email marketing can be done to either sold lists or a current customer database. Broadly, the term is usually used to refer to sending email messages with the purpose of enhancing the relationship of a merchant with its current or previous customers, to encourage customer loyalty and repeat business, acquiring new customers or convincing current customers to purchase something immediately, and adding advertisements to email messages sent by other companies to their customers.
Email marketing has evolved rapidly alongside the technological growth that has occurred consistently throughout the 21st century. Prior to this growth, email marketing was not as effective because of a lack of reach, as emails were novelties to the majority of customers and potential customers. In 1978, Gary Thuerk of Digital Equipment Corp [DEC] sent out the first mass email to approximately 400 potential clients via the Advanced Research Projects Agency Network [ARPANET]. It resulted in $13 million worth of sales in DEC products, and highlighted the potential of marketing through mass emails. As email marketing developed itself as an effective means of direct communication, a problem arose in that users were blocking out large amounts of content from emails by use of filters and blocking programs. .