- I am not sure where you got the idea of 1% fee in p2pool. But if you check the coinbase transactions in p2pool mined block, you can look for yourself that it is not so.
Well if there is an optional parameter that defaults to giving the author 1% of each found block....idk.. i would call that not free
well i just checked it for you:
main.py line 943
parser.add_argument('--give-author', metavar='DONATION_PERCENTAGE',
help='donate this percentage of work to author of p2pool (default: 0.5)',
type=float, action='store', default=0.5, dest='donation_percentage')
author fee defaults to 0.5% which is 0.25btc per block.
for me an optional donation counts as free.
buty anyway; 0.5% is the default donation if you want to see it that way.