I have seen Bitcoins being held in the news for example "Bitcoin becoming a good investment for millennial." That itself would be advertisement already. However that is the only way to advertise bitcoins; news. In my opinion, you can never advertise bitcoin by itself regardless of being in the news. From what I see nowadays, the only way you can advertise bitcoins is through the forums and social media sites. If we were able to utilize television though, bitcoin could become a huge hit thus increasing its value.