Looking for coop members! Generally I would want a donor, (25+), someone that I know, or at least heard of. Someone that wont leave the coop and that would like to build with me, and wont steal my stuff if that sounds like you drop your ign!
I suggest you to build a strong bond/relationship with a specific player before adding them. Your island is at risk when you cooped random players.
But most people don't have forum accounts, 90% of the people looking for coops; you don't see them for about 6 months