This is a direct quote from your site:

Every time a block is found, we put some of the bitcoins in our jackpot. Once a week, randomly connected to the find of a block, the jackpot is paid-out to one of the members of the pool that found the block that triggered the jackpot.

So of the bitcoins gained from mining the block you put some to the side, instead of distributing them properly, and then hand half bitcoins outo willy nilly in a lottery, which is exactly what I asked about.

Furthermore, how many is "some of"? Highly suspicious, if you ask me.