You basically get paid out if Ocean find a block. Sometimes they find a bunch in one day, other times it could be days till they find a block.

Luxor and Nicehash likely "smooth out" the payouts of finding blocks as an average. You get paid consistently whether they find blocks or not, but the payout will be less.

I like what Ocean is doing and want them to be one of the bigger pools. Thats why I mine with them.