Everyone seems to be forgetting that they host the equipment for no extra costs. This saves a lot of $$$ on HVAC, power costs, and time spent. HVAC/power costs would cost a small fortune for a farm in the range of 5-10Th (especially if these are built on Avalon's power hungry chip design.)
Is 8% APY really that bad? I think it's quite nice considering they do all the work for you.
Depends on your view of the flowback profile earned by 920GHps net power in a 300T-then-4-then-5-then... network compared to the 620 BTC you spend today for that turnkey solution, doesn't it?