Digital Marketing and online advertising for Blockchain projects can be done just like the same ordinary online marketing you do for any other project that is not blockchain related.
You can learn about digital marketing in online courses that exist in educating platforms such as coursera, udemy, etc.
I'm not sure if the normal marketing will work with blockchain, i mean some social networks don't allow us to promote the crypto projects. They have a bad concept about cryptos because it has been abused with scams and Ponzi. So if we want to make a facebook campaign or a twitter campaign to promote our crypto project, they will don't allow us at all.
I think the best way to promote a crypto project is in forums like this one. That's why signature campaigns exist.
