The marketing activities should reach the precise target group and intrigue them to seek information from your web page. When entering the web page they should be greeted with the same impression as the marketing activities gave them, and their valuable data should be stored and processed in accordance with privacy regulations to be able to give them an even better experience in the future. When a visitor leaves the web page with either a new product on its way or by being far more knowledgeable about your brand, they should have had such a good experience that they will happily recommend you to their friends and family.
Yes, this really is the dream scenario. It is not impossible, however, we are all aware of the process and the amount of work that is needed. You need to bring in external help from several agencies who might all be unfamiliar with each other's way of working. In most cases this challenge is solved by breaking down the process in parts. Design and web page first, then marketing. This often results in having to take two steps back to make corrections to the customer journey, which ultimately demands more time, money and resources.