ya, linked sockets are what you really want later on.
I use Ground Slam, my build is pretty much just a ground slammer.
Right now I have a 4 link chest piece, 3 red and 1 green sockets. so I put Ground slam in there than add attack speed (green support gem) and added fire damage and life on hit (red support gems). And that means only when I use ground slam, it has increased attack speed (30% currently) + 34% physical damage added as fire + 34 life on hit. So I just made Ground Slam super awesome!
This game SHITS on D3