The one things for sure you can promote bitcoin is social media, because a lot of people using internet and social media it is the good way to promote bitcoin. And also by going to other places where you can teach people about bitcoin, so that they will understand more what about bitcoin.
Social media is very wide place to get through people and get in touch with them all.
But it should go through the people who have more interest into this digital currency because if people dont have interest, tell them about bitcoin is useless