A message to admins.

Hi Admins!

1. When you go to a OTB tournament, talk with your friends and ask them if they have a chess.com account. a) if they do, then ask them to join your group and b) if they don't, ask them to create a chess.com and then ask them to join your group "Chess Team Holland Juniors" write it down on paper and give it to them. 

2. Go searching in "Team Holland" or whatever your country group name, and look up people on their profiles for their birthday's, or by their acting and picture (that way it's obvious it's a Junior)

3. Go join these groups: Global Teens, Global Kids, Youth, Young Chess Players International, Chess kids!, Childs play. They are all juniors group. If you find any Holland juniors, then feel free to invite them (only U18) 

I have used all these tactics in one of my biggest groupd, "The Australian Junior Chess Team" And it has been going for 7 months with 120 members. So, those are some creat tactics. 

Good Luck!

koala08

PS: The more members you get, the more popular the group will get.