The more powerful your community is, the more powerful your crypto becomes. So it's all about the community. You can attract new users to your community by good marketing through social media, events, forums etc. But it's even more complicated to retain them there. To do so, you need to continuously stick their attention to your product by releasing new features, updates and more marketing 
BurdeN I totally agree with you. The power is in the community, the best advertising is when a friend tell to a friend and they work
together. When people are united many goals can be easily achieved.
Promoting is building a community of trusted people. They will use their skills and they will find a way to promote project on various
places, internet is just one of them.