Haha. Well you get a free diamond daily technically. You can vote for the server and receive 500 noobz. And that means you can get 1 diamond from the server shop, which costs $500. Or you could get two if you tried to haggle with a player.
You also get free diamonds during special events like the server reached a large number of members, they give free diamonds to people. There's also events like the 10k members party, where many people got stacks of diamonds from the drop party.
So really we do get free diamonds, you simply have to make sure to do the work for them. ;3