The development of digital marketing is inseparable from technology development. One of the key points in the start of was in 1971, where Ray Tomlinson sent the very first email and his technology set the platform to allow people to send and receive files through different machines. However, the more recognisable period as being the start of Digital Marketing is 1990 as this was where the Archie search engine was created as an index for FTP sites. In the 1980s, the storage capacity of computer was already big enough to store huge volumes of customer information. Companies started choosing online techniques, such as database marketing, rather than limited list broker. This kind of databases allowed companies to track customers' information more effectively, thus transforming the relationship between buyer and seller. However, the manual process was not so efficient.
A search engine considers the content of the sites to determine the QUALITY of a link. When inbound links to your site come from other sites, and those sites have content related to your site, these inbound links are considered more relevant to your site. If inbound links are found on sites with unrelated content, they are considered less relevant. The higher the relevance of inbound links, the greater their quality.