I've always hoped we could attract more adult players to our server. Unfortunately, there are just SO many younger Minecraft players that it's kind of like searching for needles in a haystack. What you're doing here on this forum post is probably your best bet. But if you're going to try to attract lots of people to the server, you'll end up just running into the general demographic problem, and so you kind of have to choose between one or the other: A select group of people that you meet slowly over time, or a large public server where everyone's welcome.