The fee was always stated as being on interest and capital. Have been investing for almost 1 year. Have had over $5000 repaid in interest and principal through rewrites and normal repayments. Have paid just under 1.25% fees a total of about $60. I think it's quite fair for the 15% return I've had so far on my money.
The fees I have paid to Harmoney are a scintilla compared to some greedy stock brokers charging a total of $60 for 1 buy/sell trade; plus the big risk there is of losing capital value of shares very quickly sometimes.
I am very happy about fees v returns I get from P2P lending.
I find that the rewrites give me a second chance to reconsider my investment criteria, I think it's all good.