Advertisement will be a big help but if we will look back at the beginnings of bitcoin. There's no advertisement, it's all about internet and it's great future. But at this moment, advertisements will be a very good way to push the usage of bitcoin especially if someone influential will try to say good things about bitcoin and attracts people to use it.
Social media's are very powerful in our times, when something gets popular everyone will be on it. Like facebook's popularity, I've seen videos of bitcoin spread on the network and there are so many people that are asking about it. There's no need to take the lead about advertisement as everyone of us can do it alone by sharing our thoughts or sharing videos about btc.