blackcoinpool is really bad... i'm getting 300BC a day for about 10MH... it's been say 7500 for the past day, so that's 2,250,000 satoshi... or .0225BTC... or .00225BTC/MH
that's absolutely disgusting performance, i'm literally not breaking even with electricity on the multipool.
ED: and stats are still broken... apparently my address hasn't been used yet, even though it's displaying hash rate...
Seems like they are not mining the most profitable coin, the pools you compare it to, most likely are mining the most profitable coin all the times, exchanging it as soon as the blocks mature. I'm not sure they have implemented live coin switching to be honest.
Best bet right now is to mine at other profit switching pools and exchange to BC daily. You will get more BC and buy times will be more spread out cause it looks like blackoinpool buys most of their coins in short intervals.