While 4% may seem like a lot, from the pool point of view I think it's only fair, the risk it takes for you to guarantee a "fixed" payment to every share is HUGE, and they need a ton of money reserved to not go bankrupt.


According to Analysis of Bitcoin Pooled Mining Reward Systems by Meni Rosenfeld which was brought to my intention by Kano's post in another thread

The forum for reserve needs to be



with ln(1000) = 6.9077552789821

This means to run a PPS pool at 4% you need 1079 BTC in reserve for your chance of going bankrupt to be only 0.1%, and that is about 7 million dollars in bitcoin which many investors consider a risky asset, so really running a PPS pool is not an easy thing to do, I think F2pool has lower fees than viabtc, I have been planning on trying it, will probably switch some gears to that pool and compare.