I think the best form of marketing is word of mouth, if there is a good project then they don't need to shout it from the rooftops, people will realize the potential and they'll tell others about it, soon it will spiral and the project will be very popular.
I'm not ready to agree with this. Because there were many good projects could not find success whereas few utter jokes had become a huge projects. Promotions are important still I am also agreeing that potential and what problem is going to be solved by that crypto project is more important for its success.