It's not a server that pays-out to users for no reason. It's a server where you can:
- earn bitcoins by mining or building productively
- earn bitcoins by selling items and services (helping people with projects)
- use bitcoins for buying items from others
- use bitcoins for hiring people to help you

There's actually a world dedicated to player-to-player shops (using ChestShops). Typically, you get 50 satoshis per block on the server +10 satoshis per person on the server for each block (that means you can get up to 550 satoshis per stone block and up to 1000 satoshis per things like monster spawners), but you get much more for ores and rare materials (while you're in "The Mines"). I've seen diamonds sell for 0.01 BTC per diamond (not stack), but that rarely happens anymore.

As another note, I constantly, personally, pay users for helping me patch bugs on the server and for helping me with other things related to the server. Most of the money currently being paid out to members for mining or building purposefully comes directly from me. We will be holding a bunch of different competitions soon, and we're extremely open to feedback and suggestions from members. Most of what we have now is thanks to our members and their magnificent brains.

Here's a list of claims, and here's an in-depth explanation of how claims work. You might want to have a look at the FAQ.

The last thing I want to address is your "pay to play" statement. It's true that we require members to first purchase a prospecting permit to play. This ensures that we rarely have griefers and lowers the chances of someone joining the server, demolishing a bunch of stuff, getting paid, cashing out, and leaving. I understand that it makes some people unhappy to have to pay for the initial membership, but I assure you that most people make back the membership cost within a few days.

Edit: Thanks, DiamondCardz, for having me write-up some useful information to add to the About page.