There are many steps to consider while writing a digital marketing dissertation topics. The first thing you need to do is decide on the digital marketing and then narrow it down by analyzing different perspectives and viewpoints and also considering practical implications of your research question. You should also identify what type of data you will need for your research, how much time you will have, and whether or not you will have access to it. You can find these answers by reading journal articles and books on the subject, talking with experts in the field, interviewing people who work in digital marketing, etc.