Call me crazy but are your customers losing money? What was the buy in and monthy cost for #2? Whats the ROI on your first 2-3 rigs so far? For group buy #2 is the math 3.6 bitcoins this week divided by 290 shares meaning each share produced .0124 bitcoin this week? Whats the monthly share cost? $24 a month profit is pretty painful.
I keep a very detailed spreadsheet. Due to the 0.12 btc/share tradein options into Group Buy #6, I closed out of my positions at:
GB#2, 9 weeks, 79.4932% ROI *
GB#3, 9 weeks, 107.3295% ROI
GB#4, 7 weeks, 89.2052% ROI
(If I had been previous owner, GB#2 would have been discounted and provided: 83.47% ROI)