While I think Spazzy is pretty much the most successful provider of new people and returners with his YT-Channel, I can say that using "Discovery Freelancer RP" in the name of my YT-Channel has helped as well, since I usually write comments under videos of popular YouTubers without advertising. People click on my channel and see Freelancer stuff. That made some people curious.
So, maybe a few banners or something to use on other forums and social media would be cool. No need to shove them into people's throat when you can just make a picture in your signature that leads to Discovery.