Not many years ago, the concept of online marketing had not yet arrived. The websites were few and searchers were very stupid, so people tried to pick a good domain meant to represent the company well.
Over time, it began to proliferate the concept of SEO and with it came many new features. the content was optimized so that search engines put it where it suited to the company and had a technician’s career to see who best knew the searchers machines and was able to make easier for these content was optimized. Were times of very foolish seekers (assigned a stationary position determined based on a few words) and many traps. Words were positioned leading up to the user to visit websites that did not want were positioned, networks links were made with false promises ... a little chaos.
Years have passed and today is very difficult to trick seekers. Understand synonyms, phrases, detect when a user has made a mistake ... It is not a technical issue appearing first as these search engines are so advanced that they do not need the help they needed before. A well-constructed website is enough for the part of SEO is sufficiently well done enough not to get more return on that. Its true that thing like sitemaps are a true help, but everything is into the "do SEO right scheme". That's where marketing comes in.
No matters the technical issue but the issue of marketing on what words we choose, how we place, in what order, which content we offer... Position content it is no longer something related to the development and computer part but a part of marketing. If you make remarkable content, you will archieve sucess. So now the marketing and web design are so united because it requires both to give a comprehensive and full web solution.